I can put you together a sample pack of some preamps you can roll or if you need some specific powertubes. I know this is generally a high gain forum, but I do have some 50s blackplates that seem to be all the rage on the tan pants forums. Most of the stuff is medium gain at best, but def have some good balanced stuff for PI and whatnot. Do you need/want anything maybe for that build you were doing? Anything that goes out will be/has been tested and will match/closely match. Unfortunately, I don't have many big bottle quartets that I'm not keeping for myself
But def a nice selection of duos.