Good evening,
the screw is probably 1/4x28. If you wait a few days I can look in my box for a real wood forend and 'similar' stock. Will send pics.
I also have a 30-30AI nickel barrel with a shotgun forend. It doesn't fit either of my 258 frames. FYI..?
But I have some old stocks so let me see what.
VR,
Tom