Who made the old tricycle style landscape graders?

[dirt ditch]

Does anybody know something about the old tricycle style landscape graders. They look to be 40-60 years old and are about the size of a riding lawnmower, I think the motor is mounted to the side of duel front wheels and turn them by chain drive. The blade hangs below the center of the frame. They may have other attachments besides the blade. I saw one last week and one about 3 years ago. Both were being used to smooth and level dirt for new lawns.

 

[dirt ditch]

After hours of net searching, I came across what it could have been, a Bolens Ridemaster.
Bolens Ridemaster Blog

 

[Taylortractornut]

David Bradley and FMC made what was called a Tri trac i think but it had one wheel in the reaar that pushed it

 

[neucam]

Interesting little machine, backwards from a Allis "G" , smaller but I bet a good garden tractor/grader.