In the early 1950s my uncle was a Roof mower dealer, selling these things.
It had about a 26" blade, with a guide on the left and a little steel guard around the back. The right side and about 1/3 of the left side had no protection from the blade at all. It had 7 ankle slicing horsepower.
This is why we have a Consumer Product Safety Commission.
But I'd own one if I could find one.