The most interesting thing about the ad I found and posted, for me, is the date (1952). Between that and the roofing/shingle hatchet listing, there are all kinds of weird things going on with that ad.
Did the Plomb Tool Company (not A. Plomb) ever make and sell a roofing hatchet? Unlikely. If they did, even more highly unlikely it would be advertised using the company name in 1952. In a completely hypothetical world in which the Plomb Tool Co was making shingle hatchets in 1952, they would've been branded Proto.
I think there are two explanations for the "Plomb" in that 1952 lumbermans' trade mag ad...
It is most likely referring to the "A. PLOMB" brand name that the California Tool Company was still using as a reference to its well-known predecessor. The A. Plomb Tool Company was established in 1917 and it became CTC in 1927. As we all know, though, CTC continued to manufacture "A. PLOMB" tools for many years and the tools were often marked with both "CALIF-TOOL" and "A. PLOMB". If they were still continuing that practice in the 1950's, and in the hands of a third party (Barr Lumber Company) selling all kinds of various products (Stanley, Goodell-Pratt, etc), not nearly so circumspect as Plomb Tool Company or CTC, they didn't even get it technically correct, dropping the "A.", creating an interesting spin on the Plumb v. Plomb saga that doesn't get much attention.
I'm thinking the example that
@Ole Slewfoot posted is early. Pre-CTC. But the A. Plomb Tool Company was too small for Fayette R. Plumb to worry about, and CTC using A. PLOMB as a brand not much bigger or a bigger worry. The irony is that there was almost certainly much more overlap between the Plumb product line and the A. Plomb or CTC product line using the A. Plomb brand, with shingle hatchets being a prime example.