Did you look to see if they are Jay scott grips? Also check out sile grips. As Bob Wright said, with Herrett and fuzzy farant (they don't look like a pair of fuzzys) that in short, it has to be a pair made by one of the big custom grip makers of the time.
I've noticed a similar checkering pattern from jay scott, so good luck in your search.
Winchester 73, the TFL user that won the west