Typical annoying spot vs. unknown

I guess this is quite a standard spot but I'm a little lost. CO is a breakeven reg, I have him running at 16/12. I have no hands on the button but I do have an old note from a previous database saying he c/called AJo on a rag flop instead of cbetting so I presume he's bad.

$1/$2 No Limit Holdem
5 Players
Hand Conversion Powered by weaktight.com

Stacks:
UTG ($210.80)
CO ($241.40)
BTN ($203.60)
Hero ($203)
BB ($202.55)

Pre-Flop: ($3, 5 players) Hero is SB
1 fold, CO raises to $6, BTN calls $6, Hero calls $5, 1 fold

Flop: ($20, 3 players)
Hero checks, CO bets $13, BTN calls $13, Hero raises to $40, CO folds, BTN calls $27

Turn: ($113, 2 players)



Preflop, I think 3betting is an option but with the unknown player on the button I choose to call.

Flop, how's this raise size? Anybody prefer donk/3betting? I don't think I'm going to be raised by the CO frequently with worse, I have no idea about the button though.

Turn, ugh... I hate every option. Bet/call and hope that he gets it in with AXd or two pair seems pretty damn optimistic. Bet/fold I think is dumb against an unknown. Check/call seems dubious. Am I c/cing to call a river bet on a non-pairing non-diamond river? If so is it not better to pick another option since I doubt he has a high bluffing frequency here. That only leaves check/fold and against an unknown that seems retardedly nitty.

HALP!

edit: now with added HH

I check here alot because it's an action killer for your hand and you want to keep him in. I'm not folding at any point though.

Pre I like the flat with the unknown (likely fish) in the pot. Against 2 regs 3b is fine here .
Flop is a c/r on this texture against a bad reg. Sizing is on the small side considering a psr is to 72 so I think I make this a little bit bigger.

Yeah looking at this one again I definitely think I messed up the flop raise size pretty badly. I should have sized it to leave a pot sized shove or so on the turn. A bigger raise size would also encourage the fishy to get his draws in on the flop and would also hopefully look more like a draw so he can spaz and call down light.

yeah raise the flop more. Turn is a standard bet/call