Matrix-12 front panel touchup

Anyone have a technique for touching up the front panel of an Oberheim Matrix-12? It’s a plastic overlay with a shiny base layer and a clear matte textured top layer. In one spot the top layer is worn away leaving the shiny layer exposed. Any ideas on how to convincingly touch up that matte clearcoat?

Alternatively - anyone know of a source for a replacement overlay?

What if you removed the matte overlay completely (we had an Xpander all shiny like this, and it looked pretty good!), and then got a matte vinyl sheet to replace the overlay? Talk to a place that does vinyl wraps for cars - they will have this stuff, and it comes in 5-foot wide rolls. Maybe you could just buy a 2x5-foot piece. I think you could just press on a piece slightly larger than you need, then trim around the base with a razor blade.

Sam’s method works great if the area missing is an obvious plastic looking edge. But if it is more a worn or feathered looking edge you cal buy some art triskett mask and put that with an area a little larger than the affected area and use a photograph mat lacquer spray and carefully spray very light layers and let each dry in between successive sprays use controlled overspray to blend the spray into the edge upto the triskett mask. When you’ve sufficiently covered the area with the spray carefully remove the mask. Make sure you use something like a prep solvent or automotive tack cloth to remove and dirt, oils and contaminated from the areas needing repair before applying the mask. It works well for repairing areas on guitars finishes and should work well to touch up synth bodies.
As always, dont work fast or impatiently, slow careful light layers not quick heavy ones…mask off a area on a similar metal piece or on a small area on the underside of the synth as a test,/practice area to see if the results will be what your exacting standards require. Always do a test before doing anything permanent on a finished product.