I really was not looking for another rototiller, but this one got my attention. I am pretty sure it is a Model 23 made in Troy, NY by ROTOTILLER, INC. It has a 3hp Clinton engine and may be the first year for the Troy-Bilt Horse style handlebars. Earlier models had a more straight style of handlebar. This one also has hard tires. No worries about air leaks on this one. My thought is that this one was made in 1959 or early 1960 after Porter Cable got controlling interest in Rototiller. I say this because the manual shows a new numbering system for parts and their format for stamping the s/n on the tillers changed. Later in 1960 PC took over Rototiller and changed the model numbers and the colors to green and white.