Just stumbled across this. I can confirm that the prop in the museum is not from the Firefly off Portstewart.

I was onboard the Coleraine dredger “Bar Maid” that was attempting to recover the whole aircraft (my Dad was the skipper). A team of army divers along with several local divers were trying to do this. Sand was cleared from around the wreck (relatively intact) using blowers powered by compressors and then a strop attached around the prop hub. This was to be lifted by the ship’s crane.

During the lift the ship heeled over considerably, then righted quickly. We thought the strop had broken, but on raising the crane wire it turned out to be the prop and Griffon engine.

The whole unit had parted from cleanly where it connected to the main airframe. The rest was too full of sand to be lifted, so it snapped at the weakest point.

I remember seeing “last inspected XXXX 1953” on the engine which was recovered to Coleraine where it sat on the quay. There were two conger eels still inside! It was then transported to an enthusiasts group in Enniskillen. Not sure what happened to it then. I have the only photos of this recovery somewhere and there was a detailed article in the local Coleraine Chronicle soon after by the then editor Hugh McGratten (also an aviation enthusiast).

The rest of the Firefly is still there and apparently there is film footage of local fishermen from Portstewart rescuing the aircrew. Hope that helps.