All-in Donk bet on river on missed flush board w TPTK

This line is often very strong. Villain just called pre and limp called OTF. Looks passive calling station or a trapper to me.
I think you can't go terribly wrong with any line here. You can make an exploitative fold because his line looks very strong, but if you want to play theoretically correct so villain can't exploit you, this would be a call.
I checked this with Snowie and it would call 68% of the time.

A few thoughts of mine.
I understand that Sb-s minbet is ridiculous OTF but wouldnt it be better raising less?...Im thinking of £1.50-1.70 (on that board id lead out with that kind of bet anyway).
Id personally try to keep that pot smaller but a raise is necessary.
Youd have £5.70 in the pot OTT when im thinking a tad bit bigger than half pot size bet again....such as £3.00.
And check OTT.
Depending on Villains move i evaluate. Youll know if hes got something.
You still have a top pair hand OTT. I wouldnt be too keen to call off my stack like that.

When I'm having a hard time I just look for tendencies at the micros. This player obviously shows strength here and people at the micros barely lie. We can run an equity simulation but I think you have too little equity for the call here. I'd fold in such situation

Turn i would bet more 1/2 pot tbh as villains like this will do this often at these stakes and betting smaller on the turn allows the pot to be smaller if he donks on the river, and also we need villain to get to river with worse one pair hands. I think i good line is flop raise, turn 1/2 pot, river 33-50% pot and fold to shove.

As played this is a fold, villains hardly turn up with worse in this spot + uv only got a one pair hand.

As Hesticus pointed out you are most likely beat here. I think that very few people in the micros are capable of making a bluff in that spot. I'm expecting to see a full house here.
I think you called this hand, so can you please show the results cause I'm interested to know more about those minraises ( 0,25$) on the flop.

I think check behinde on turn would save you money to call river
Bank would be not so big, and player on the riveer would no go all in. may be he would bet 60% it's a little beit more that HERO bet on turn.