Overpair OOP multi-way, facing river shove

1/3 (9 handed)
Hero: QdQh UTG Stack: 670
V1: CO Stack: 340
V2: UTG + 2 Stack: 500

History with V1 (MABG) - was buying in for 200 and had lost several buy-ins (I think I heard him say he was in for 1000 total and most recently bought in for 300 two hands before this one). Wasn't playing a tight short stack strategy, but wasn't just looking to gamble-gamble.

A specific hand w/ me - With 150 in his stack he over-called my EP RFI when he was in the BB w/ 77 and donked a 2h4h4d flop for 1/3 pot into 2 opponents, and then shoved his stack when I raised his donk bet.

OTTH -

Hero RFI to 15 w/ QdQh from UTG (670 stack), UTG+2 calls (500 stack), CO calls (340 stack), BTN calls (400 stack)

FLOP: 9s 6s 3c (58 in pot)

Hero bets 40 (thoughts on sizing?), UTG+2 calls, CO calls, BTN folds.

TURN: 9s 6s 3c Jc (178 in pot)

Hero checks (???), UTG+2 checks, CO bets 85 fairly quickly (200 more behind after this bet), Hero calls, UTG+2 folds

RIVER: 9s 6s 3c Jc Kd (348 in pot)

Hero checks, CO thinks for 15 seconds or so and then goes all in for 200, Hero ?

I felt unsure of whether to check or bet the Flop and how much to bet, same with the Turn - would love advice and thought process on that. On the river, all the draws bricked, but an overcard did come. I wasn't sure if this Villain was capable of betting 200 as a bluff, but I'm also getting a pretty good price to call. I'm also not sure if Villain was capable of value betting a K that paired the river (Ks Xs). I felt like he'd likely check back if he binked TP on the river. If that's accurate, then it's just sets (that didn't raise the flop) or 2 pair that value bets this river.

Looking forward to any thoughts, thank you!