$200 effective, I open KJo to $10 mp, 2 calls from older nit regs.

Flop Q94r I cbet $10, 1 call.

Turn Q94 K. I bet $45, nit reg calls.

River Q94 K 2. Action?

You are out of position? Close... maybe block bet like 40 and fold if shipped on vs a nit.

Check/evaluate with an eye towards folding. A nit shouldn't be betting much that you beat. AQ/KJ/KT but AQ doesn't always bet and KJ/KT don't always bet or call flop. Your going to see more JT/KQ/K9/Q9/sets when villain bets

Yeah oop to both players

I'm shoving the river. It seems strange to bet the turn and then get mubsy and check/evaluate the blank river card. If we're worried about the nit making a big hand on this K turn, then why did we pot the turn OOP? Would the nit call/slowplay the turn with a better hand as the board straightens out? Is a nit calling pre with Q9 or K9? KT? KJ? The better line would be to check the turn if we think the card is bad.

I like the check/call small, fold to big most of the time. Mix in some block bets, since there's some value in your hand. Mostly seems as if the only draw (jT) got there, lots of KQ that he was afraid of you having AQ on the flop, and sets though.

bet/fold small.

Nitregs aren't raising the river with anything less than Q9/KQ here (and I think they would have raised the turn. And they're more likely to give up a busted straight draw then bet if checked to.

Bet to see if you can get some value from QJ/QT, maybe even AQ depending on the type of nit.

I'm not certain I like shoving. While it 'looks bluffy' to a lot of old man nits, they still may not feel like they need to look you up - so you lose value from Qs and get value owned from better hands.

I think you're ranging him too wide if he's a nit. Q9, K9, 44, 22 and even KT and KJ are often autofolds pre from a nit. And even if plays KT and KJ, as a nit he's folding to the c-bet. I think his range on the river is AQo, AQs, KQs, JTs, QQ, 99 and that's about it. You might even discount AQ because he might well fold that to the turn bet. Even to a small bet on the river, I think he's folding AQ most of the time; everything else beats you. I check; I might call a very small bet, but otherwise I'm folding. Nit almost certainly has you beat, and if not, he's almost certainly not bluffing or value betting with anything you beat.

Of course, a lot of this depends if he's a real nit. OP - when you say Nit, how much history have you got, and how nitty are we talking?

This is the best advice out of all the replies IMO.

bet $50