So my fire-sale Star Trek Next Generation could use a little help with the cabinet. I don't have the room here for a full restore/repaint but two things require attention:

The rear of the backbox must have gotten wet at some point, it looks like it has swelled and is soft in a couple of spots. I'd like to remove and replace it but don't want to damage the rest of the head in the process. Were these panels glued in, nailed in, both? What's the best way to remove it without damaging the rest of the head, just knock it out with a mallet? Best way to attach the new back panel, just wood glue and clamp it in?

The rear of the main cab is also a little chewed up but I can fix that with resin. Need to replace the two rails that the cab rests on when it's tilted up though, so same question, were those glued on, nailed on, both? What kind of wood do I want to replace those with?

First time doing any real serious cab work and I'm more than a little nervous about it.