Dude,

I think you have it wrong.  SS doesn't need heater power.  My educated guess is that the 5 VAC winding was disconnected.

If your power trafo's 5 V. winding has a CT and you use a 5U4, take the "raw" B+ off that CT.  In all other situations, take the "raw" B+ off of pin 8 on the rectifier socket.

The pin 8 connection works for a 5U4, but there is a tad less hum using a CT, when it's available.

Think seriously about sending the unit to Mr. Deckert for a check out.  If the DINGBAT that owned it previously was stupid enough to put that Weber stuff in, additional problems might be lurking under the surface.