Hello! I bought an amp chassis on ebay and bit off more than I can chew.

It is a Sound City SC100R, without speakers and reverb tank.
I would like to turn it into a head. The amp is very appealing because all components are laid bare and there are no ICs.

Attached is the schematic and some other blurb about the amp.
Also traded as Londoner L100 and Sound City SC100R
https://www.vermona.com/support/vermona-heritage/ search for 100G

Which Reverb tank works with this amp?
How do I go about checking the device over without getting killed in the process?
Cheers,
Bernd.