If we give MP a reasonably cautious range by LLSNL standards that now made only excellent hands such as sets, top 2P hands, made straights and NFDs below AThh, we have 33.98%, assuming that drunk guy has all kinds of crazy crap but at least some piece of the board. There's $220 in now so really we can just jam it.
http://www.pokerstrategy.com
Board: 7h5h6s
Equity Win Tie
MP2 33.98% 33.71% 0.27% { Th9h }
MP3 48.29% 47.41% 0.89% { 77-55, 98s, 87s, 76s, 43s, Ah9h, Ah8h, Ah7h, Ah6h, Ah5h, Ah4h, Ah3h, Ah2h }
CO 17.73% 16.81% 0.92% { 44+, A7s-A6s, K7s-K6s, Q7s-Q6s, J7s-J6s, T8s-T6s, 96s+, 86s+, 72s+, 65s, 54s, 43s, 32s, J7o-J2o, T7o, 97o+, 87o, 76o, 65o, 54o, 43o }