Small bet on turn sounds good.

I'd bet 1/2 pot on the turn or so. Put the PFR on the installment plan.

Calling the flop here stinks imo.

I think Xastons advice is very bad for this level. Your call on the flop is great. You don't want to fold out the lone or a two-pair/set that could improve to a perfect second best hand. The analysis Xas makes would be correct against better opponents, but not here.

However, you need to bet some amount on the turn. I think you have two options, betting $2.70 hoping that the deepstack calls and the smhortie pushes and thus re-opens the betting. Or betting >$3.90, since they were willing to put $3.90 on the flop that should be the minimum of your bet on the turn unless you're going for the get-shorty-to-push-and-re-open. I'd probably bet like $4.70 or something and hope for a river spade that pairs the board. Either way I am all-in on the river.