[J Paul]

It is possible for the reasons Arran mentioned. However I remain skeptical on this particular one. Notice how the speaker screws have been overtightened to the point that the screw heads have been pulled into the veneer? Someone's had their ham-handed mitts on this poor thing, and did it no favors by doing that. The same person could very well have added that 51/52/early 60 and 38 escutcheon to a cabinet that may have had no escutcheon when they acquired it.

You think that's ham-handed, you should have seen the way they connected the replacement electrolytics!    I had one eyeball on the schematic the whole time I was overhauling the chassis.  By the way, it sounds great now, and I implemented a couple of your performance tweaks as well.  Making the cabinet look new again with the damage you saw (and then some) is beyond my woodworking skills, so I took the "do no harm" approach and just cleaned it up and applied Restor-a-Finish.  Here it is: