Slowly getting back in the saddle after a ten year layoff, so hope this isn't too basic. (Narrator: It's probably basic)

1) Any way to get PT4 HHs converted? Sorry for raw feed.
2) How bad is my logic here?

Opponent only had a handful of hands on opponent, so no real reads. Appeared "normal-ish" pre-flop in that sub ten hand sample.

Hand #771893033 - Holdem(No Limit) - $0.05/$0.10 - 2021/04/10 14:59:23 UTC
Blitz Poker 6-max Seat #1 is the button
Seat 1: locogoa ($15.63)
Seat 2: 0ud0ntn0 ($15.06)
Seat 3: nood1g ($10.00)
Seat 4: MountainMan20 ($12.84)
Seat 5: idiotbluffing ($9.88)
Seat 6: DisIsMyTime ($12.43)
0ud0ntn0 posts the small blind $0.05
nood1g posts the big blind $0.10
* HOLE CARDS *
Dealt to MountainMan20 [3c Ac]
MountainMan20 raises $0.25 to $0.25
idiotbluffing folds
DisIsMyTime calls $0.25
locogoa folds
0ud0ntn0 folds
nood1g folds

* FLOP * [5c 7h 4d]
Main pot $0.62 | Rake $0.03
MountainMan20 checks
DisIsMyTime bets $0.21
MountainMan20 calls $0.21

Not a board I can really cbet ever, so decision point after he cbets 1/3rd. I think we have too much SD value to CR our double gutter + BD FD + over card here, but maybe this is wrong. Plus I don't think I have too many hands that want to CR for value (77 and some smaller 55 frequency I guess), but again perhaps I need to be doing that with some overpair combos + draws.

* TURN * [5c 7h 4d] [Ad]
Main pot $1.02 | Rake $0.05
MountainMan20 checks
DisIsMyTime bets $0.68
MountainMan20 calls $0.68

Hit the overcard, so pretty easy check-call.

* RIVER * [5c 7h 4d Ad] [7d]
Main pot $2.31 | Rake $0.12
MountainMan20 checks
DisIsMyTime bets $1.86
MountainMan20 calls (???)

Expect him to check behind a lot of SD driven hands here, so a little concerned he bets this particular card after I call the turn. Still, do we think there are enough bluffs here from a GTO perspective (even if the pool underbluffs)? Or do these have enough SD value at this point that we are just no good here enough? Thinking like 66, 65s, 54s, 98s for bluffs, plus some of A5s, A4s that may want to try for value still that we chop with?