Not familiar with that tractor.
That said, MTD is huge and makes a huge percentage of the lawn tractors in the country. Brands made by MTD but badge another name include Dynamark, YardPro, Weed Eater, Noma, Sears Craftsman, Murray & Cub Cadet. MTD makes the low end (non-commercial) John Deere tractors and Cub Cadet. Most anything purchased at a box store (e.g. Lowe's, Home Depot, Costco...) are also made by MTD.
So, back to your bagger, I'd widen your search to a generic search for a lawn tractor bagger. Just spot a tractor that looks like yours and there's a good chance the bagger may fit yours. I'd start with Craigslist.
