Happy Ending

I AM playing at the annual Benidorm chess festival held in the Gran Bali Hotel, where I am seeded 75th out of 384 entrants in the U2000 tournament.
Just for a change, I managed to come up trumps in an ending in today's round two.

Black offered a draw after playing 36...Kg7-f6 in Spanton (1880) - Andres Parreno Cueto (1766)

Black is a pawn up, but I was ahead on time and felt I should be able to hold a draw if my attempts to win came to nothing.
37.Ke2 Ke6 38.Rc5 Kd7?
This gives White chances. Analysis engines reckon Black should hold comfortably after either 38...f5 39.Ra5 g4 40.Rxa6 g5 41.Ra5 gxf3+ 42.Kxf3 Rd2, or 38...Ke7, eg 39.Rxg5 f5 40.g4 fxg3 41.Rxg3.
39.Rxg5 Re6+ 40.Kd2 Rd6+
Komodo9's choice for a long time, but it comes to prefer 40...Kd6! when 41.Ra5 Re5 seems to hold whether White goes for the pawn ending after 42.Rxe5 Kxe5 43.Kd3 Kd5, or the rook-and-pawn ending after 42.Rxa6 Rh5 43.h3 Rg5.
41.Kc3 Re6
41...f5 prevents White's next, but then comes 42.h4, eg 42...Ke7 43.h5 gxh5 44.Rxh5, and at least one of Black's f pawns drops anyway (Komodo9).
42.Rg4 Re2
The passive 42...Rf6 will not save Black, eg 43.h4 Kd6 44.Kd4 Rf5 45.Rg5! (the hasty 45.Ke4 is well-met by activating the rook with 45...Rb5) 45...Rf6 46.Re5 Kd7 47.Ke4, and White's advantage is huge thanks to his dominant pieces and Black's pawn weaknesses (Komodo9/Stockfish8).
43.Rxf4 Rxg2 44.Rxf7+ Ke6 45.Rc7 Kd6 46.Rg7 Kd5?
This makes White's task easier.
47.Rd7+ Ke6 48.Rd2 Rg1 49.Rf2 Re1 50.Kd3 Re5??
A serious positional blunder that makes the win relatively trivial by allowing White to get down to a pawn ending.
51.Re2 Rxe2 52.Kxe2 52...Kf5 53.Ke3 a5 54.b3 g5 55.a3 c5 56.h3 Ke5 57.a4 Kf5 58.f4
This pawn sac is the only way to win, but it is also very simple to calculate. The game finished:
58...gxf4+ 59.Kf3 Kg5 60.h4+ Kxh4 61.Kxf4 Kh5 62.Ke5 Kg6 63.Kd5 1-0.