I'm assuming that the 1.23 in the stats is the villian's aggression factor. 1.23 means a good amount of calling relative to betting. This may mean he calls too often or he is passive or both. I find some passive players check call with 2 pair or a set and then put a big bet on the river sometimes. I wouldn't rule out something he made earlier in the board than the river card. Given that he puts money in the pot preflop 73% preflop of the time he could have just about anything for two pair j7, j9, 79.

all possibilities for a flush: 36 ways
you beat: 21
you lose to: 15

Of course some of the low hands he is not going to limp because he folds outright about 27% of the time preflop. As a rough estimate let's take out the bottom 27% of the flushes possible. 27% * 36 = ~10. And let's take out AsKs since he would probably raise preflop.
so...
you beat: 11
you lose to: 14

If you assumed he had the flush (read) you look to be a slight underdog to be winning. But if you think other hands are possible then this is worth at least a call.