Here's a happy ending! These two Philips B3X08A sets came in for restoration, more or less simultaneously (what are the chances!?)
. One had a missing dial glass, with a crudely made perspex plate. Fortunately I could have a duplicate dial plate made from the good one, which I contracted out, as that kind of thing is above my pay grade. Not exactly like the original, but a vast improvement. A vinyl sticker on perspex.
I recapped the usual culprits, electrolytics and paper caps. The main electrolytic cans were left in place as they support the ferrite bar antenna.
Both sets developed the same issue after turn on (what are the chances!?)
. About 3 minutes into playing, the volume faded and any attempt to turn up the volume resulted in distortion. After posting my query about this on this forum, it was diagnosed as leaking EL84 output valves. Since I laid my hands on replacements they play perfectly.
The closest schematic I could find was the Philips B3X02A. Close enough!
https://www.radiomuseum.org/r/philips_b3x02a.html
Another minor change was fitting an RCA socket to bypass the original (unusual) socket for the pick-up input.