He was making grips in the 20s, but what we know as Kearsarge started in the early to mid 1930s. Long after he officially closed Kearsarge Woodcraft, he was still making custom grips with his oak leaf design, and I am sure that at least some of the grips we are seeing were made as late as the ealy to mid 1970s. The 19-2 I own that beloned to him is a 1964 DOB gun, and the K frame grips on it are from a bit later no doubt. I also suspect that a couple of sets of smooth stocks I have seen posted here on this forum, with "unknown maker" attributed to them, are examples of his work but I can't prove it.
Obviously the grips we see on RMs and older N frames are mostly from the time era those guns were being produced, the time he was advertising in
American Rifleman. But the bottom line is, he was still carving stocks long after the other vintage stock makers ceased production, and made at least a few sets not too long before he died in 1989. What I would really like to ID is the differences (in tooling marks and similar) between Wendell's very early hand carved stocks and the ones he did later that were done with a dremel. I think Geoff Moore had at least 1 set of his early hand carved stocks, but I am in the dark as to the whereabouts of Geoff and his collection.
The initials were one of his features he offered, put on the bottom of the right stock in a nice monogram style carving. You can see 1 example with the DW initials (interesting!) in McGiverns
Fast and Fancy Revolver Shooting. Now lets see if I can find Charles' own stocks from my 19-2, with his own CBW on them: