I bought this '57 GS in the mid 60's, and it is pretty much the way it came from the PO.
I was looking to see what it would take to put a new seat cover on, and it looks like the cover that is on there was put on with nails. There are no prongs on the under side of the seat pan to hook the cover to, and there are no fastener holes that would indicate that the cover was a not the original. It looks like the nails, and there are no slots or indication that they are screws, were put in with some sort of gun, since, at one spot where there was indication that a nail was attempted, but not inserted, there were two overlapping indentations that look like the hammer of a nail gun.
Was this a BSA method of seat cover installation? If not, how were the original covers attached to the metal seat pan?
Thanks for any information.