k.. well my thought process would be that even though he's been a rock, it's a beneficial situation for him on the button against 2 random hands and all playing for good amount of money with each knockout.. his (and your) M is semi-low, but your effective M is even lower so you need to make a move really soon if your intention is to try and win and compete with the bigstack..

If you call and win your right next to the leader and solidified your shot at headsup.. if you call and lose, you finish a solid 4th

Only 5 hands has you dominated (AK, AA, QQ, KK).. highly doubtful he has AA since u have an Ace or QQ since you have a Q.. plus I don't think he'd go all in with AA or KK.. I think he'd want to play a big pot with one of those hands and just make a norm raise (even though that would look suspicious that he just doesn't stick it all in)..

If you are sure to put him on 4 hands, 2 of them being really unlikely, then fold.. if not, a call is at least even money or better

All in all I'd call and take my chances, I know I can go a long time 4handed without seeing a better hand and blinds come around really fast