"I've achieved my first priority, which was to make a donation to ensure that the men of Bomber Command who lost their lives during the Second World War will be remembered with pride for generations to come," said Mr Munro, one of only two New Zealanders to take part in the daring World War II raid - the other being the late Leonard Chambers.
"As an aside, the agreement has enabled the medals to stay in New Zealand."
Mr Munro, of Tauranga, said he was astonished and very touched by the interest generated by his quest to raise funds for memorial's upkeep.
There was a delicate balance to be achieved between raising funds for the RAF Benevolent Fund and ensuring his medals were preserved for future generations of Kiwis to appreciate, he said.
"Lord Ashcroft's very generous proposal represents the best way of attaining both these objectives. I am extremely grateful to him." he said.
Lord Ashcroft was flying yesterday, but tweeted from his flight: "Very pleased. A win win for everyone."
London auction house Dix Noonan Webb has waived its fees and out-of-pocket expenses on the understanding that Motat makes a further donation of 10,000 ($19,500) to the RAF Benevolent Fund, which looks after Bomber Command Memorial in Green Park, London. The memorial honours 55,573 aircrew, including 1679 Kiwis, who were killed during World War II.
Mike Neville, the director of fundraising at the RAF Benevolent Fund, welcomed the final outcome.
"Les' sacrifice and Lord Ashcroft's donation will help assure the long-term future of the memorial," he said.
Mr Munro yesterday said he had been well supported by his family ever since he expressed wishes to sell his medals.
"Their support was the main thing," the former pilot said. "The family all have copies of the medals, and the same with the log books, so they're not deprived of any major memorabilia of mine. I think we have satisfied all parties."