I don't know about that particular model but I'll offer some suggestions.
Use clear caulking to seal any cuts or tears. While it's still wet, close the door onto clear wrap to form the caulking to the door frame. Tape tightly closed and leave alone for 24 hours. When dry, remove the clear wrap.
Another way we would fix small tears in the plastic door seal was to use Super Glue. They might still use it in the industry.
You might try these guys, first it would be best to get your gaskets profile using calipers for accurate measurements:
Custom Refer GasketsI've never needed a gasket made so I can't vouch for them but it's a resource that could help.
And then there's the old standby, the Sears Repair Center. If you're near one, and if they're not too busy, there might be a tech interested in the challenge of finding a substitute for you. But of course, you'll still have to cut and glue it so find out what glue they use for tears in gaskets these days. You could try an American Appliance Center too.
I use to be a Montgomery Wards Service Manager and those gasket seals were often a problem when damaged. My techs had their tricks to restore them or the sources of new ones, I'm just vaguely aware of them now after all these years.