The aircraft were actually shipped from Halifax Nova Scotia. The aircraft had been flown up to Canada and assembled for shipment on the Bearn at RCAF Dartmouth. They were physically pushed across the US-Canada border at Houlton Maine into New Brunswick and then flown on to Dartmouth.
In fact a team from the RCAF actually were sent aboard the Bearn to continue to help assemble the aircraft and they also ended up in Martinique.
I have a picture of two of the Belgian Buffaloes(NX93B, NX90B) at RCAF Dartmouth, prior to them being barged out to the Bearn in Halifax Harbour. I do have a series of other shots, but this shot is the only one to show the Belgian Buffaloes.
There was an article “Forgotten Reinforcements” by noted Canadian author Carl Vincent, in the June 1974 issue of Aircraft Illustrated about this event.