your correct, except for the MTD part. They had nothing to do with that bike other then getting the western auto contract and replacing it with a smaller sized bike in like 1971. It was made by General Appliance which was the maker of trail horse bikes. "Wizard ss300" was the western auto name, early off the line correct engine was a Briggs 3hp, but most survivors have showed up with the Tecumseh H30's on them. I think WA wanted briggs due to what they sold on the wizard line of lawn equipment, but briggs really did not want their engines one MB's and did not want to supply them to bike manufactuers so that ended quickly.