I would strip the chassis down to individual components and paint them all flat black, then re-assemble and make sure the paint hasn't caused any binding issues.
I'm not sure how much room you will have inside the body once it is mounted so you might want to remove the window plastic and spray the inside of that gloss black, after all the last thing you want to see is your custom mounts and the chassis
If you have a decent amount of room then you could mockup the engine and interior but remember that a really Enzo is slammed, that's why it has the switch to flip up the front nose cone so you don't hit it on speed bumps.
Can you take a photo of the body sitting on the chassis, just put some temporary spacers between them so we can get an idea of the ride height.
I like the rims, they fit nicely... have they already been converted to fit an XMOD??