diff --git a/src/proc/asset.cpp b/src/proc/asset.cpp
index 44af7ae67..dd98bc7a4 100644
--- a/src/proc/asset.cpp
+++ b/src/proc/asset.cpp
@@ -48,24 +48,28 @@ namespace asset {
   
   
   Asset::Ident::Ident(const string& n, const Category& cat, const string& o, const uint ver) 
-    :   name(util::sanitise (n)), 
-        category(cat), org(o), version(ver)
-  { }
+    : name(util::sanitise (n))
+    , category(cat)
+    , org(o)
+    , version(ver)
+    { }
   
   
   /** Asset is a Interface class; usually, objects of 
-   *  concrete subclasses are created via specialized Factories
+   *  concrete subclasses are created via specialised Factories
    */
   Asset::Asset (const Ident& idi) 
-    : ident(idi), id(AssetManager::reg (this, idi)), enabled(true)
-  {
-    TRACE (assetmem, "ctor Asset(id=%lu) :  adr=%p %s", size_t(id), this, cStr(this->ident) );
-  }
+    : ident(idi)
+    , id(AssetManager::reg (this, idi))
+    , enabled(true)
+    {
+      TRACE (assetmem, "ctor Asset(id=%lu) :  adr=%p %s", size_t(id), this, cStr(this->ident) );
+    }
   
   Asset::~Asset ()
-  { 
-    TRACE (assetmem, "dtor Asset(id=%lu) :  adr=%p", size_t(id), this );
-  }
+    { 
+      TRACE (assetmem, "dtor Asset(id=%lu) :  adr=%p", size_t(id), this );
+    }
   
 
   Asset::Ident::operator string ()  const
diff --git a/src/proc/asset/sequence.hpp b/src/proc/asset/sequence.hpp
index 9f895ce36..c24cfd3c0 100644
--- a/src/proc/asset/sequence.hpp
+++ b/src/proc/asset/sequence.hpp
@@ -64,13 +64,13 @@ namespace mobject {
 namespace session {
   
   class Track;
+  typedef MORef<Track> RTrack;
 }}
 
 
 namespace asset {
   
   
-  typedef mobject::MORef<mobject::session::Track> RTrack;
   
   /**
    * TODO type comment
@@ -78,6 +78,7 @@ namespace asset {
   class Sequence 
     : public Struct
     {
+      typedef mobject::session::RTrack RTrack;
 
     public:
        void detach() { TODO("Session-Sequence registration"); }
diff --git a/src/proc/asset/struct-factory-impl.hpp b/src/proc/asset/struct-factory-impl.hpp
index f27b32347..59a61deba 100644
--- a/src/proc/asset/struct-factory-impl.hpp
+++ b/src/proc/asset/struct-factory-impl.hpp
@@ -62,6 +62,8 @@ using mobject::Session;
 using mobject::MObject;
 using mobject::session::Scope;
 using mobject::session::match_specificTrack;
+using mobject::session::RBinding;
+using mobject::session::RTrack;
 
 using lib::Symbol;
 using util::isnil;
diff --git a/src/proc/asset/timeline.hpp b/src/proc/asset/timeline.hpp
index ee60508ef..50937591f 100644
--- a/src/proc/asset/timeline.hpp
+++ b/src/proc/asset/timeline.hpp
@@ -58,6 +58,7 @@
 #include "proc/mobject/mobject-ref.hpp"
 //#include "proc/mobject/session/binding.hpp"         ////TODO avoidable??
 //#include "lib/p.hpp"
+#include "lib/element-tracker.hpp"
 
 
 //#include <vector>
@@ -70,12 +71,12 @@ namespace mobject {
 namespace session {
   
   class Binding;
+  typedef MORef<Binding> RBinding;
 }}
 
 
 namespace asset {
   
-  typedef mobject::MORef<mobject::session::Binding> RBinding;   ////TODO why defining this into namespace asset? shouldn't it go into mobject::session ??
   
 //  using lumiera::P;
   
@@ -85,6 +86,8 @@ namespace asset {
   class Timeline
     : public Struct
     {
+      typedef mobject::session::RBinding RBinding;
+      
       RBinding boundSeqence_;
       
     public:
diff --git a/src/proc/assetmanager.cpp b/src/proc/assetmanager.cpp
index dcd18b7b7..8e562dc26 100644
--- a/src/proc/assetmanager.cpp
+++ b/src/proc/assetmanager.cpp
@@ -103,11 +103,11 @@ namespace asset {
   /**
    * registers an asset object in the internal DB, providing its unique key.
    * This includes creating the smart ptr in charge of the asset's lifecycle
+   * @throw error::Invalid in case of invalid identity spec
    */
   template<class KIND>
   ID<KIND>  
   AssetManager::reg (KIND* obj, const Asset::Ident& idi)
-      throw(lumiera::error::Invalid)
   {
     AssetManager& _aMang (AssetManager::instance());
     DB& registry (_aMang.registry);
@@ -123,14 +123,13 @@ namespace asset {
   }
   
   
-  /** find and return the object registered with the given ID.
-   *  @throws Invalid if nothing is found or if the actual KIND
-   *          of the stored object differs and can't be casted.  
+  /** @note the KIND of asset needs to be assignable by the actual stored asset
+   *  @throw error::Invalid if nothing is found or if the actual KIND
+   *         of the stored object differs and can't be casted.  
    */
   template<class KIND>
   P<KIND>
   AssetManager::getAsset (const ID<KIND>& id)  
-      throw(lumiera::error::Invalid)
   {
     if (P<KIND> obj = registry.get (id))
       return obj;
@@ -204,7 +203,7 @@ namespace asset {
   AssetManager::remove (IDA id)  
   {
     PAsset asset = getAsset (id);
-    for_each (asset->dependants, detach_child_recursively());
+    for_each (asset->dependants, detach_child_recursively());             ///// 
     asset->unlink();
     registry.del(id);
   }
diff --git a/src/proc/assetmanager.hpp b/src/proc/assetmanager.hpp
index 6f5c29c10..51b7b416b 100644
--- a/src/proc/assetmanager.hpp
+++ b/src/proc/assetmanager.hpp
@@ -21,11 +21,13 @@
 */
 
 /** @file assetmanager.hpp
- ** Proc-Layer Interface: Asset Lookup and Organization.
+ ** Proc-Layer Interface: Asset Lookup and Organisation.
  ** Declares the AssetManager interface used to access individual 
  ** Asset instances.
  ** 
- ** These classes are placed into namespace asset and proc_interface. 
+ ** These classes are placed into namespace asset and proc_interface.
+ **
+ ** @todo 10/10 meanwhile I'm unhappy with some aspects of this implementation //////////////TICKET #691
  **
  ** @see asset.hpp
  ** @see mobject.hpp
@@ -79,7 +81,7 @@ namespace asset {
       
       /** find and return corresponding object */
       template<class KIND>
-      P<KIND>  getAsset (const ID<KIND>& id)  throw(lumiera::error::Invalid);
+      P<KIND>  getAsset (const ID<KIND>& id);
       
       
       /** @return true if the given id is registered in the internal asset DB  */
@@ -102,8 +104,8 @@ namespace asset {
        *  @internal used by the Asset base class ctor to create Asset::id.
        */
       template<class KIND>
-      static ID<KIND>  reg (KIND* obj, const Asset::Ident& idi)
-          throw(lumiera::error::Invalid);
+      static ID<KIND>
+      reg (KIND* obj, const Asset::Ident& idi);
       
       /** deleter function used by the Asset smart pointers to delete Asset objects */
       static void destroy (Asset* aa) { delete aa; }
diff --git a/tests/components/proc/mobject/session/session-modify-parts-test.cpp b/tests/components/proc/mobject/session/session-modify-parts-test.cpp
index 6c49bf2b5..0fe02991d 100644
--- a/tests/components/proc/mobject/session/session-modify-parts-test.cpp
+++ b/tests/components/proc/mobject/session/session-modify-parts-test.cpp
@@ -58,7 +58,6 @@ namespace test    {
 //  using asset::PTimeline;
   using asset::PSequence;
   using asset::Sequence;
-  using asset::RTrack;
   
 //  using lumiera::Time;
   using lumiera::Query;
diff --git a/tests/components/proc/mobject/session/session-structure-test.cpp b/tests/components/proc/mobject/session/session-structure-test.cpp
index 6844e29d4..5f725c0e5 100644
--- a/tests/components/proc/mobject/session/session-structure-test.cpp
+++ b/tests/components/proc/mobject/session/session-structure-test.cpp
@@ -46,7 +46,6 @@ namespace test    {
   
   using asset::PTimeline;
   using asset::PSequence;
-  using asset::RTrack;
   
   using lumiera::Time;
   
diff --git a/tests/components/proc/mobject/session/timeline-sequence-handling-test.cpp b/tests/components/proc/mobject/session/timeline-sequence-handling-test.cpp
index 4651a96bd..190d9bc2a 100644
--- a/tests/components/proc/mobject/session/timeline-sequence-handling-test.cpp
+++ b/tests/components/proc/mobject/session/timeline-sequence-handling-test.cpp
@@ -53,8 +53,6 @@ namespace test    {
   using asset::PTimeline;
   using asset::Sequence;
   using asset::PSequence;
-  using asset::RBinding;
-  using asset::RTrack;
   using asset::Pipe;
   
   using lumiera::Query;