Someone asked for pictures.
Here are some of the pieces and a large woofer. Note the lines on the pieces I did that to make sure where everything went, and later used it for a screw pattern.
Here is one inner cabinet put together with the paint I chose for the interior. A couple of things about the paint;
1) I chose the smooth as opposed to texture finish.
2) They couldn't make Black, so I got dark gray. I could probably have asked them to put more black tint in it, but it was Sunday at HD.
3) It is like painting with pudding.
4) It seems to fill well.
5) I have been painting with a brush, and then using a small roller to smooth it out.
Here is the inside of the inner cabinet after one coat.
I messed up a few things on the other inner cabinet, and it needs some bondo work before painting. I'll post those later.