I recall seeing somewhere (that of course I can't find now) that around and before 1994 the model IV fuselages were somehow specific to the engine selected. As in, you had to let Skystar know what engine you planned on using when they jigged up the fuse. Does anyone remember what was specific to this?

I have an early 94 fuse that was bought with a 912 FWF package and has the instrument panel braces welded to the cross tubes for the "large" panel. Was the location of these the only difference?