Thanks for that info, but I'd actually powered it up before seeing your post
(at least as far as the Rx and Heaters, so that would have put the HT on also). But, it did power up OK and seems to be working on the Rx side, though some Servisol might be beneficial.
I'll add checking (replacing) those resistors on the "To Do List".
I cannot remember when I bought it (many years ago), but it was secondhand from one of the big ham radio dealers. Seemed fairly good and had what looked like brand new GE 6146's in the PA, which tested very well indeed.
I see there's a Yahoo group for the 520/30 and 820/30, so I've just subscribed to that.
B