Hi Shaun,
I've been working a Mustang for the last few months. I know, sounds like a long time, but when your scratch building most of it, it takes alot of time. Anyway, I recently began priming and painting and had the same question you did. Much of the data available is confusing and at times conflicting. Because of this, I pulled out some photos of the NASM's Mustang. They finished the wheel bays overall yellow chromate with no distinction between the main spar and the rest of the bay. The inside of the gear doors looks to be aluminized lacquer as are the main struts.
I figure if it's go