I can't fold this river... can I?

[SteveGriff]

Ok. Two questions:

Do I bet this river?
Do I call this river raise?

Villian is pretty much a straightforward player. VPIP 23% PFR 13% over 300 hands. Sorry for crap hand history format.

Table "Ottumwa" Seat 1 is the button.
Seat 1: Samanta (£56.25 in chips)
Seat 2: Hero (£127.25 in chips)
Seat 3: Thomps007 (£55.20 in chips)
Seat 4: Makarov24 (£136.88 in chips)
Seat 5: Jaggoo (£167.73 in chips)
Seat 6: blind5 (£40.79 in chips)
Hero: posts small blind £0.50
Thomps007: posts big blind £1
Jaggoo: posts big blind £1 + posts small blind £0.50
blind5: posts big blind £1 + posts small blind £0.50
----- HOLE CARDS -----
dealt to Hero[Ah Ks]
Makarov24: folds
Jaggoo: checks
blind5: checks
Samanta: calls £1
Hero: raises £1.50
Thomps007: folds
Thomps007 sits out
Jaggoo: calls £1
Thomps007 sits back
blind5: calls £1
Samanta: calls £1
----- FLOP ----- [7h 8c 7c]
Hero: bets £1
Jaggoo: folds
blind5: folds
Samanta: calls £1
----- TURN ----- [7h 8c 7c][Kd]
Hero: bets £2
Samanta: calls £2
----- RIVER ----- [7h 8c 7c Kd][6h]
Hero: bets £2
Samanta: raises £4
Hero: calls £2