I have an old Mastercraft (MTD) 10-28 snowblower. Trying to get it all fixed up but having an issue with the model number. The plate seems to have had some of the numbers and letters work off. All I can get is 3 7 8 1 515. Serial number is 238053. It has a tecumseh 10 hp engine, it’s model number is HM100 159106L SER6269D. Anyone able to help me figure out its model number?