[Arran]

Yep, brand Z was noted for bloated tube counts especially in the early 40s. There was absolutely no reason for using a pair of 6X5s as rectifiers other then that purpose when they could have used a single 5Y4/5Y3/80, and the way they were used had to be one of the stupidest power supply designs of all time. That was another trick to bloat tube counts, using single triodes when they could have used dual triodes, for some unknown reason Philco did this with their 670 series sets. Another that always bugged me was the use of a 6J5 and a 6H6 rather then using a 6Q7, it bumps a 5 tuber up to 6 but still does nothing for performance as the 6H6 diodes are often tied together or one side is neutralized by tying the plate and cathode together.
Regards
Arran