This is for sale near me and I'm getting tempted to go pick it up but I'm having a problem determining if it's really the one designed for a Bolens tubeframe or if it was "made to fit"? The owner claims it was fitted to a tubeframe.
See if he can send you a few pictures of the mounting brackets. That will give us a good idea if it was mounted to a tuber. Typically they have two mounts coming out the back of the seat pan as well as one around the steering column and then a few down below near the foot rest and treadle pedal. That does look nice and almost like it is made of wood.