Never heard of a 10Y until now. Have to check it out
If you get a chance, I would recommend listening to the 10Y. It's one of my favorite DHT tubes now.
Can you help me identify the transformers? Looking at your third photo, the two on the left are OPTs and the one on the right is the power xfmr. What is the fourth one on top and the two underneath the chassis?
The smallest transformer in between the power trans and the OPTs is a 8 hy choke. The two open frame transformers under the chassis are 6.3 CT filament transformers for the 10Y tubes, each powering a 10Y with 7.5 vdc.
The brown-based tube looks to be a rectifier, but I see four power diodes too?
If you are referring to the potato masher, yes, it is a 5R4 rectifier for B+. The full bridge diodes are for the 7.5 volts DC heating each 10Y.