i got a Metrix u61b , was considering this (
http://roehrentest.de/) a few years back , but it isn“t a cheap project so i never built it .
got the metrix quite cheap and never looked back .
does everything i need and no need for charts , only the daatsheet . tests for shorts and leakage , too
( gotta make me some adapters , though , only got octal and noval atm )
https://jacmusic.com/Tube-testers/Metrix/shorts.htm