What is the correct play at the river and is the hand range analysis below appropriate?

$5 Re-buy ($1,500 Gtd) – SB vs BB (two largest stacks collide)

We are at the post-ante stage, with about 25 players remaining out of a field of 150. The pre-flop pot is 2,000 and I’m chip leader with a stack of 66,000 (M>30). 

Small blind: 400; Big blind: 800; Antes: 800 (total)

Play folds to the small blind who’s second in chips with 47,700 (M=24). He raises 2.5x to 2,000.

I don’t know much about him other than his VPIP/PFR stats – 21/16 over 120 hands. His perception of me is probably a TAG or standard reg (my stats: 19/15).

I sit on the Big Blind with: Jd Th

I call and we go to the flop.

Flop: Ts 7d 5s

Pot: 4,800

My stack: 64,900; Villain stack: 46,100

Hero bets 2,168. I call.

Turn: Ts 7d 5s As

Pot: 9,136

My stack: 62,700; Villain stack: 44,000

Villain bets 4,068. I call.

River: Ts 7d 5s As 6d

Pot: 17,272

My stack: 58,600; Villain stack: 39,900

Villain bets 15,268. Action on me- shall I call/fold?

I’ve attempted to range the villain below. 

Given villain’s bet sizing on the river I think we can remove most, if not all, of his marginal range. 

Monsters:

-Flushes. Combos = about 20

-Strong Aces (AK, AQ). Combos (33.33% discounted)=16

These mirk the waters between strong and marginal but i think, given the SPR at the river is only 2.5, we might count these as either monsters or a proxy for weird marginal bets.  

-Set and two pair. Combos (after appropriate discounting)=22

These are heavily discounted due to the villain’s bet sizing on the turn. With 3 spades on the board at the turn, I expect him to bet slightly heavier than 44% pot. I decided to count all A6 combinations (of which there are 9) and discount the remaining two pair + sets by 66.66%.

-Straight (98). Combos (50% discounted due to the unattractive third spade on the turn)= 8

Total monster combos: 66

Air:

-Turned gutshots + flush draws (KQo, KJo, QJo with a spade) that missed the river. Combos= about 17

-Complete whiffs (including 5s or 6s turned into a bluff). Combos=?

In order to justify calling, villain’s air range must be around 33 (ie. he needs to be bluffing 1/3 of the time). So there basically need to be 16 combos of whiffs in his range. Do you think that this might be the case given:

-his wider range from Small blind and

-i flatted his bet on the turn in a show of weakness.

Any input much appreciated because ranging these small vs big blind is so difficult. Actual outcome: I folded.