This occurred after a rebuild (as required for the Canadian Department of Transport) at Abbotsford Airport, BC, Canada, by Aerovive Ltd over a 7-month period in 1962, and costing C$40,000, including complete refrabricing of the wing and tail surfaces.
According to the RAF Museum's PDF record for the aircraft, it;
Flew from Abbotsford Airport runway No. 18 to the Fraser River at Sea Island - took off with the hull resting on a specially constructed detachable 4-wheel 'dolly' from which it lifted off when flying speed was reached. The dolly rolled to a stop at the end of the runway.As it was not equipped with brakes, as can be seen above, it was retarded before the attempt by a rope attached to a (presumably full) Shell fuel bowser. This '40-minute test flight, flown by Slim Knights' was probably one of the most 'testing' take-offs in the type's career, notwithstanding the many open sea rescues by Stranraers in the war.
In this next photo we can clearly see that the dolly wasn't proof against the aircraft rolling to the starboard on the take-off run, but the potential disaster was averted.
Today this aircraft survives in the RAF Museum Hendon, last of its breed, and last complete example of the large, multi-engine pre-war biplane flying boats.
(And it has a secret. No one knows what unit codes it wore in service. If you can find evidence, the RAF Museum would be delighted to hear from you.)
Credits: Canadian Aviation Museum images. Thanks to Andy Simpson of the RAF Museum for his help and the various people who shared their memories of this hairy flight with me.