I'd leave it. The black paint looks flawless, why tempt fate? Unless you think you can do better. I've got lots on the shelf that I would like to do over but they also show how far I've come.
There have been a couple of threads over on the Randy Ayers site showing dynamite builds of the COT. I think you want to stay with the AMT COT chassis and add detailing to that. The current kit has the hood separate to make that easier. You just need to add an engine (with associated FI plumbing) and the front cage parts which you might be able to make from one of the older kits. Just my opinion but it seems it would be a lot easier starting with the chassis that fits the body to begin with.
Great foil job on the skinny trim around the windows and wheelwells, I know how difficult that is! Love the color, stripe delete was a good choice. Great model!