Constant removal and replacing of that screw and nut caused it to dig deeper and deeper into the fore-end until the nut was bottoming out. We used to have a repair for that by drilling out the hole slightly oversize then insert and glue in a PRE-BORED dowel patch. If you don't pre bore it you'll never get the hole properly aligned at the other end! It is a 4BA screw and nut as I recall. You could just patch the outer ends of the hole to suit. If you have the nut I've got a bolt you can have