Up for sale is a beautiful 1948 Valco National tube amp. The amp is in working condition and sounds good. There is some wear to the tweed but nothing crazy. It looks like the back was replaced at one point with a piece of thin plywood. Good thing no one sees the back anyway.
When you put the volume at max it will crackle out at times when I have a lot of bass in my tone. I have a reverend guitar that has a "bass contour" tone knob and it cant handle too much low end it seems. I've never had an old amp like this and am not much of a player in general, but it powers on and plays loudly with no issues other than what I just mentioned. The tubes light up and etc. As far as the plywood back, I'd just cut the middle out or cut a grill into it.
As noted, there are some cosmetic issues but for the most part the "tweed" is in good shape for its age.
I'll take the backplate off and photograph the internal components some time soon.
The 1948 date is based on running the serial on the back against a valco database. It could be off, but based on my research it's a 48.