But by yesterday, 52 veterans had registered for the unveiling of the memorial, which is being built in a central London park.
The stone pavilion in memory of the 55,573 crew killed is the result of three years of fundraising, which has reached $11.5 million after promotion from singers Robin Gibb of the Bee Gees and Jim Dooley of The Dooleys.
"It will be a little moment of triumph for all of us," said Des Hall, 87, a flight engineer in Lancaster aircraft operations over Europe.
"It will be acknowledgment of what we did to help win the rotten war."
More than 6000 New Zealanders volunteered for Bomber Command and about 2000 were killed.
A pilot of Halifax aircraft, Bill Petersen, 90, said that four years ago, he had gone to England for what was supposed to be the last reunion of his 102 Squadron.
"There were not as many there as I had hoped but then there's a hell of a lot of us not here now."
He had paid his own fare to attend the last reunion, saying travelling business-class was a revelation after being cramped in a freezing cockpit on wartime operations over Europe.
Tom Whyte, a rear gunner, who turned 87 on Tuesday, said: "I've filled in the form and I think it sounds like a pretty good do, with all keen types.
"Otherwise, I had felt I could not afford it."
Frank Prebble and Ron Mayhill, who were both awarded the Distinguished Flying Cross for their service, said they were much looking forward to the trip and to remember comrades who did not survive.
The association in New Zealand has 200 members.
Outrage over the way veterans were treated last year at the 70th anniversary of the Battle of Crete prompted Monday's election pledge by Prime Minister John Key to the Returned and Services' Association national council.
Mr Key said that, if re-elected, National would pay for Word War II veterans to attend an overseas 70th anniversary official commemoration linked to their service. Commemorations include the anniversaries of the battles of Monte Cassino and El Alamein, the Pacific War and D-Day.
The promised policy includes business-class flights, accommodation, meals and medical care, compared with the $2000 of support given to the Crete veterans who had to pay out of their own pockets, arrange their own itineraries and stay in modest accommodation.