Hannelore: That's amazing. (I also won a game ages ago from a similar position, and I should have recorded the details for posterity.) I NEVER resign until it is IMPOSSIBLE for me to win!!
grenv: As white I would have doubled at move 35, once gammon was out of play. As a matter of principle black must pay to play for a miracle. Psychologically, black is very likely to drop and pat herself on the back for saving gammon.
The only other thing I noticed on a quick scan is that at move 29, black should have moved a blot to the midpoint (black's 12 point) in order to give herself a return shot in the event white rolls double six.
grenv: Of course you are right ! Theory says that if White has beared off all checkers except his last which get hit, then he is a 92% favourite to win the game. It is probably even worse with an open 6-point and 5 checkers on the 1-point. So it is very clear that Black would have had to reject any double by White. I was just imagining the case where Black would have taken the double ! Agreed with alanback too, the double should happen just after that gammon was not possible any more.