The 'stubs' referred to were a by-product; the trimming of the thick end of the horseshoe nail, rather than being made from old nails removed from a horse's hoof after having been 'worn'.

I think you are pursuing a good project here and I'm following it with interest. When I have digested and examined your body of work (when it has settled a little), I think I may be able to add a few points of interest, clarify one or two threads and raise one or two questions.