Off the top of my head, I wouldn't do it.
First of all, it's inside the amp so no one would know. I have seen some radio projects done on polished (probably a poly coating) wood that looked purdy.
Wood is an insulator... so it might work. But wood is also organic, and generally has a pretty high moisture content (much higher than ordinary fiber board material) which could lead to conductivity. This could cause arcing, fires, or just plain lousy tone from bleeding off the signal. This would not be good.
It gets quite hot inside a tube amp chassis. If the wood dries out, it could lead to cracking. Wood is not exactly the best dimensionally stable material. This would not be good.
Dumble. Well, I don't know but I would be real surprised to find wood circuit boards inside of his amps. Not only are they noted for their tone, they are also noted for their reliability.
Wood... of any type, no matter how exotic, would seem to have too many disadvantages to really be practical.
Besides... I love point-to-point wiring without any circuit boards.
