Has anyone seen this kind of behavior?  The original model (obtained from a colleague) is pictured here:

After suppressing some parts and making other changes too numerous to list, I get the following image:

SW Premium 2014 SP5.0 64bit under Windows 7 SP1.  All the individual parts look fine.  Everything seems to be in the assembly when viewed from different angles (though always with some graphic anomalies), and I can't find anything wrong with the display properties of the various parts or assembly; but I'm too much of a beginner to know what I'm looking for... -- John Willett