Two thoughts - gluing down some tough leather to the toe with perhaps Barge Cement or covering the front of the shoe with 3-M 5200. I don't know how I would get a smooth, good looking finish with 5200 but it would last and protect. (You could go too thick and sand it smooth later.) 5200 is an adhesive we used to glue sailboat decks down to the flange of the hull. Once set, it is stronger than the inter-laminate bond of fiberglass. Those decks do not come off. I've glues sole rubber onto cycling shoes to make them cleat walkable and good floor friendly. I think that job is going to outlast the shoes. (Cleat bolts, straps, uppers ...)
The Barge approach should work. It would be far easier and when the leather is shot, you might be able to peel it off and renew. I'd cut and fit the leather, mask around it with tape, use powerful solvent to remove the original shoe gloss and leather dye and keep the masking tape in place until the Barge is applied and the leather stuck on. Edit: making the leather you apply the appropriate black is easy. Black shoe dye. Any cobbler will have if. One of those cotton puffs on a wire handle will apply it easily. (Probably comes with the jar.) Really easy, fast, dries fast and it's really black! (And will blacken all sorts of other things. Just don't get carried away, You won't be able to find your house in the dark.)
Last edited by 79pmooney; 10-16-22 at 10:50 AM.