That is a little weird. Mine has a Yard-Man / Yardster stickers on the pulley cover. This guy says he found one with a Corvette body. You can see the brackets to attach it.
Did DB make an exact copy of the Yard-Man? Did Yard-Man make an exact copy of the DB? Were they the same company with different divisions? I also don't know what motor it is on it. It looks original. Has brackets for the pulley cover that line up perfectly, etc...Thanks!
Sears, Wards, etc carried various models of bikes and karts throughout the sixties and seventies that were badged with their logos, or logos of the originating MFGR, etc. Marketing.
So with an original tag on original paint, your machine is telling us the real story. When I was searching around, I saw some photos under the "U-ship" site of the belts and linkages. I think they might have been offered with various power plants as well.
I started digging into the history of both manufacturers.
So, maybe it was mfg. by Yardman and sold under the DB name tag? I think if it had actually been mfg. by DB it would never of had a Yardman sticker on it.
"After Sears purchased the company, it added a great number of farm implements to the David Bradley line of equipment. Many of these implements were manufactured by other companies and merely sold under the David Bradley name. Soon these implements out-numbered products actually manufactured by the David Bradley Works. Nevertheless, whether made by the David Bradley Works or by someone else and merely sold under the David Bradley name, some products became very popular with farmers."