Vintage Motorcycle engine, perhaps Flying Flea

This is an incomplete Royal Enfield engine, perhaps a Flying Flea as its another of my late dads, (he was a Flea "Nut). The crank turns and engine numbers match. We have tried to mark numbers with marker pen so that you can see where they are. 1 is V2259, 2 is 6334 and 3 is 2902 matching. Hope the pictures show enough if not please let us know. The engine weighs just over 8kgs. We have another two boxes of dads stuff to sort out yet, and we do not know exactly whats there. Thanks for looking. Postage would be around £7 if you cannot collect, we are NR19. As a plus ro this items description, we have just got the cylinder for the Flying Flea engine, but it looks like it will need a new liner. A friend of dads saw the advert and brought it over so we are adding it to the lot, bur of course the postage will have to be more, thanks.