[Arran]

I had a look, online, of photos of the underside of other 620 chassis, and they seem to have a mix of tubular and Bakelite block caps. The latter are a good idea to restuff as the terminals on top do double duty as terminal strips for the resistors, and other wiring, what is good about this example in particular is that it looks like they were all left in place by previous repairmen, like whomever added the Olson brand caps in there.
As I mentioned I have a model 620 myself, and whilst I haven't used it in a long time I can recall that it was a good performing radio, likely due to the tuned RF amplifier stage. I can't remember what the difference was between the 620 and the 630, I believe that the latter had a shadow meter above the dial, the 640 had a shadow meter and a push pull output stage I think, but it also had a bigger chassis.
What I would not mind getting is a late version of a 116B, it had a different cabinet then the early version, my late uncle had one years ago. The early version looked like the 620 but with a larger cabinet, and a fancier front panel, the rest had the same dark lacquered poplar covered arch, with shoulders, just wider, and deeper.
Regards
Arran