Thank you guys for the encouragement. I left my SD card at home, but I have a few inside shot of the amp.
I used good quality components: Alps RK50 pot, Takman REY resistors, Solen FEP Teflon caps in the signal path, WIMA bypass caps, Nichicon Audio caps, Teflon tube sockets.
I made PCBs for the 300V power supply and front-end DC heater. Transformers are from Sumr. Chassis are ordered from eBay.