The magna-trac mystery tractor on the Motomow site was made by Magna American corp.

Magna American Corporation
P.O. Box 90 Hwy 18
Raymond, Mississippi 39154
Manufacturers of Choremaster, Tillsmith, Hustler and Private Label yard and garden equipment.

Magna American (Magna Engineering Corp.) is better know for developing the Shopsmith 5-in-1 woodworking machine, ceased production in 1966. The present day Shopsmith Corp. is not connected to Magna American.

Magna, as Magna American referred to them, models included the Briggs & Stratton Model 130292 5 h.p. chain drive tillers no. 500594 and 500595. These models used horizontal shaft Briggs & Stratton engines.

Dub-L-Til was a series of models that were equipped with more then the normal 4 bolo-tines per mounting plate. The 5 h.p. and 8 h.p. chain drive units had 8-bolo-tines per mounting plate. The 3-1/2 h.p. gear drive model had 6-bolo-tines per mounting plate. Magna American flyer for the Dub-L-Til claims "The aggresive tines, dig deeper with a faster forward motion across the ground, along with that smooth, easy-going ride. Takes the strain out of gardening and makes tilling a pleasure". The 5 h.p. and 8 h.p. models used horizontal shaft Briggs & Stratton engines, the 3-1/2 h.p. probably used a vertical shaft Briggs & Stratton engines, the flyer I have does not show the engine.

I found another reference that said they made the Magna-trac tractors.

That's all I found so far. Walter