Given this is mostly forum leans heavy towards 80’s and 90’s metal. I’d say Marshall and mesa boogie. If you collected the numbers I bet the most prolific amp here is nmv and mv Marshall’s, probably modded by 3-4 various builders here. Followed closely by mark 2/3/4’s, maybe dual rectos.
I actually owned this amp! It was my first amp ever. Sounded like shit but I was SO FUCKING STOKED when I put a Boss Metal Zone in front of it. I wish I felt that stoked about ANY gear now ?