Found this tOday while out thrifting and hitting up pawn shops. I'm thinking Adam or something along that line, but for some reason the pin & joint doesn't click for me. Piloted 5/16x18 with a 1/2" collar, 1/4" on each side. The pilot is sleeved in wood with square shoulders vs rounded and the pin is flat on top vs pointy or rounded. Super dense, but also super boring maple I believe. It feels like it should be a good breaker, as I bought it for breaking. Anyway, any ideas?