Very sweet project, GTI! It is already quite impressive and not even finished yet (though, sometimes seeing all the work involved before the paint covers everything up really shows how impressive...)
On a philisophical note, don't let the 'toy' features get you down. Many of the things you're correcting were designed with consideration for fast & cheap production - very appropriate for a toy. The fact that any of it is useful as the basis for a display model build is a testament to Hasbro's dedication to making quality products when the name of the game is high volume and (relatively) slim profit margins. When you're finished, I expect it will definitely 'fill the bill' as a display piece.
One question: are those steel bolts you're using to screw into the aluminum armature parts? If so, I'd recommend using some plumber's silicone sealant "grease" on the threads to prevent any galvanic corrosion causing problems later.
Keep up the good work!
Regards, Robert