I think the two wheel tractor you are wondering about in the photo may be a David Bradley. Back in 1980 before I had any interest in tractors I had a neighbor with a 1950 vintage DB, he called it a "walking tractor" and used it mainly to push snow with a front blade. Sears Roebuck sold them at one time, possibly other places did.
Hi, I have a walk behind like that only mine is a Simplicity model L-1 with single forward speed and no reverse. I have a blade for it,sickle mower, cultivators. Simplicity also made a model like the one pictured.