The components after the trannie is for that specific model. You could probably ditch that, or use whatever the new trannie mfg recommends.
The 25yF should NOT be an electrolythic! Film/oil/paper.. (Well, it should if you're planning on doing a complete original job, which is *impossible*)
Chokes? No idea. Ask Oliver @ TAB-Funk.
ERG 110? Voltage tube or slow turn on device?
The vari cap is for optimizing hf response... I think? It's in the feedbackloop.
I don't think it's worth clonning though. They're not that expensive.
Best pentode baby I've heard though.