You'd think most players would raise small blind limp with 88, 99 , KK. So unless he back door-ed a boat with 98,78,K8 ( which he could have 11 combos of; dumped suited variants and gave him 8♠9x, 8♠7x) we are probably good here? Also id imagine he has all sorts of trash flushes in his BB limp back range, that he could play like this, and maybe some bluffs like Q♠/J♠Xx @ a small frequency.

1. PF - why complete?
2. FLOP - why x/r if you dont have any reads?
3. RIVER - I bet there. Dont see any FH in his range. 77+ raise pf. I dont expect anyone calls 2x overbet OTT with 2 pair.

I would definitely shove the river. Villain has a lot of worse flushes in his range given his 100% range preflop. Yes, he has some full houses, but KK/88/99/77 aren't in his range ever, so that leaves him with 98/78/K8, which aren't that many combos considering the fact that he raises some of those hands atleast sometimes and compared to flushes, he doesn't have that many of those full houses.

Checking the river makes it awkward. Villain is probably not going all-in with his worst flushdraws here, and it's tough to come up with many bluffs. I guess I'd fold once you checked the river, but the check seems like a pretty big mistake to me.

I also prefer jamming the R myself for the reasons the other guys mentioned.
As played, I'm calling (too high up in our range/Villain can be jamming worse/turning stuff into a bluff etc)

Must shove, he wont bet much worse himself both as bluff and for value and if he does, he will also call a shove anywys. If he has a full, x/call or jamming doesnt matter outcome will always be the same.

What's your reasoning for checking the river? Other than that I think you played it well. Obviously not super GTO but sometimes you gotta get all the dough in the middle versus the fun players

Jam river, He calls with most flushes, you may find the odd hero call when they decide you have 79 as well as the coolers.
Snap river as played. Its hard to hit a backdoor full house and he should raise 77,99,KK pre. + if we fold the nut flush here then we never call the river.

So what did you do ?
And what the outcome was ?

pre is fine
flop is fine
turn sizing is really interesting tbh
river i'd be snapping it off quite quickly as played, but easy jam imo