Thanks grant ..have you checked the b+ and eht ?
b+ should be 170v, I would say eht should be about 26kv
I have attached the schematic, there is a a table of components differences for 29" and 33" so you can check those

i have a bench meter ..you do have a eht probe?
with the amount of chassis swapping and adapting you are doing you should check the eht, I check and monitor b+ and eht on every repair I do let alone any mods done to chassis. I also check heater voltage when using new batches of flybacks, you need a very high spec multimeter or a bench meter to do this
Ahhhyou order item and they send you a link once confirmed
Thanks for clarificationcorrect tube