[stigmata]

Villian was desribed as an "observant player who didn't get out of line", -- I figure this means he is tightish. Therefore, I am findind it difficult to find a hand that would cold-call preflop and then improve on the turn.

Surely 77 would fold the flop? Would he cold-call 78s or A7s from an EP raiser?

It's difficult to know, but if he did improve on the turn his most likely hands are now either a busted straight draw or perhaps a two-pair with Ax. This would suggest a check-call.

On the other hand, if a read confuses me, and I don't know what to make of it, I prefer to just ignore it and play the hand straight-foward.