i'm a tube amp builder myself (i also do fx and repairs and mods :)
i've build 2 amps up till now.
The first one is a Mashall "18 watter" (1974x) lite2b, modded to my taste.
I took the tubes (2x mullard 12ax7, 2x mullard el84, 1x mullard ez81 all the tubes where in nos condition)...