So, I've been buying some old Mac-II era carcasses (gutted cases) on eBay and whatnot, intending to mod them into semi-modern cases. However, backplates generally need modification, and it's hard to make that work well.

I would like to try just cutting out most of the rear and 3D printing a new one to match, with proper port-holes for an ATX motherboard, PCI cards, etc. (rather than just being lazy and using the standard metal cutout.) But haven't had much luck finding PLA filament that's a good match for the old "Platinum" case colors.

Any thoughts, sources, etc? TIA.