OK, since stock is not totally important. Go with the Meier rear fender ($60) and the XR Mini Racer "Mudder" front ($50). You could run an oval front fender (VMX - Peter is a good guy), those run $30, but are as close to original as possible. DC Plastics carries the original square number plate for $35. Also carries the side panels for $65 and Decal set for $22. BE advised that the DC plastics are a rough finish and will require sanding & polishing to get a smooth finish.
For the fenders be sure to tell them that the original color is flash red (orange). When you do the frame repaint be sure to use automotive paint (rattle can) and tape off all the ignition ground points.
As far as exhaust, DG still has the '85 silencer ($104) but no main pipe/manifold. Put an ad on VintageMX.us for the exhaust system.
Complete plastic kit
http://www.dcvmx.com/xcart/product.php? ... at=&page=2 Good luck!