wwall: 29.Bf4 instead of 29.b4 probably fails to 29...Rxg3 30.Bxg3 Bxg5, threatening 31...Rc1Without 32.Re1, Black would play Rc1, winning the Queen for Rook.
32...Bh4 also looks good, winning the exchange
Perhaps 35.Rfc2 is better than 35.Rcf1 so that White can take the open file.
Maybe 39.R5f4 is better than 39.Rf8+
40.R1f6?? looks bad. Maybe 40.R8f4 or 40.R8f7+ can draw
40...Qd4+! is better than 40...Qxb4? 41.R6f7+ Kg6 42.Rf6+ Kg5 43.Rf5+ Kg6 44.R5f6+ and draw by perpetual check
Faster seems 43...Kg5 44.Ke3 Kh4 45.Kxe3 Kxh3 46.Ke3 Kg3 47.Ke2 Kg2 and the black rook pawn queens after ...h5-h4-h3-h2-h1=Q
After 49.Kc3 Kc5 50.Kd3 Kd5 51.Ke3 Ke5 52.Kf3 Kf5 53.Kf2 Kf4 54.Kg2 h4 55.Kf2 b5 and Black easily wins