Hey Para the images in your original post are now visible as well too for some reason. Anyway thanks mate.

Ridolpho I did think that, but it looks like a bit more word than the cross screw or just replacing the screw wire. I also would not mind keeping the square end on my butt-stock bolt if possible. Looking at it now I reckon I will have to remove the U-plate for the rear of the fore-end for the cross-screw anyway unless I patch the hole and then move the hole for the cross-screw forward so it does not enter the inletting for the U-plate.

I have an idea that does not sound too heretical, hopefully: I reckon I could gouge/chisel out a small square around threaded rod/screw wire on one side of the fore-end enough to grab it with a pair or pliers and twist it out, then I could do my repair, drill the hole out for the new wire/rod or plug it with dowel and then try the cross-screw. Then just plug up the gouged/chiselled area and make it all flat. Not butchery is it?