Thanks for the guesses everyone.

I thought gun rack myself but the holes are so small I don't think It would hold very much. The holes are not threaded if that helps.
so I think it's the aftermarket ( installed by owner) & not Factory


1959 3100, original 235/3 on the tree w/overdrive. Carter YF 2100S carb, 205/75/15 w/front sway bar