.... and you threaten Rxh7+, bravo and double bravo!

what about 32.Rg1?

32 R1g1, and R1g4 would threaten mate on h4 (and h7!). so black has to play 32 ... Rh8, 33 R1g4 Kh5 34 Kg2, and I don't know if you can make any progress from there, because Kg3 fails to e4+. Maybe 34 Rg1 is better, keeping black tied up, and what can he do then? the b2 rook can't move, the h8 rook has to guard the pawn on h7, and if the bishop left b8-h2 diagonal that would give you a chance of the R1g4, Kg3 mate. So probably a draw, but black's completely tied up.

Actually, the move was worth consideration, and I ought to have mentioned that I had considered it. The problem. it seemed to me, is pretty much as no_genius remarks - there doesn't seem to be any good way of making use of the hold on the g-file. The mate threats just peter out into nothing. I was also mildly concerned about the possibility of ...Rb8; ...Rb8xb3, to spring the trapped rook. In that situation, Black's a-pawn could become dangerous.

So white would be happy with a draw here, as black can repeat Kf4.

In a way I was using the prospect of a draw as a threat, though I was still hoping that White might have a win in the position, provided, of course the BK did not return to f4. When there is a large difference in ratings, this is one advantage the lower rated player has...