There are limits to my experimentation on the MP-2..
My experiences have been that, as the MP-2 were pretty much build for that 80's big hair metal saturated sound, trying to reduce gain by using lower gain tubes for a more crunchy sound really doesn't work too well.
I'd suggest using a fairly high gain 100-105 tube in pos #1, and go for a 95-100 tube in pos #2, most likely a long plate, like a Ruby or Mullard Reissue.
I'd avoid the JJ 110-115 tubes; not that there's anything wrong with those, they just don't crunch.
You could try a 12AT7 in pos #2, but you'll loose out on high gain solo distortions, at least unless using a high gainer in pos #1 and use voicing 8 with some additional juice from the Overdrive parameter.
Microphonicity is most always a sign of aging tubes.
Are the foam tube stabilizer pads in place? If not, the bottles might shake more - and we don't wanna shake dem bottles unless it's party time, do we now..