I sent a slightly torn but pretty good seal to a member of this site in the UK for them to use as a template for making up new seals.
I think it came to nothing - cost was too high, he decided to patch up that seal instead and use it.
I still have a new black seal in a drawer at home, but it is not for sale. It has never been installed, but it still looks old & tired, just natural deterioration from age I guess. I bought it over 20 years ago. My machine (which is not working, I don't have a motor for it) has the original light blue/grey seal, in fair condition, heavily repaired with light grey silicone.
I do wonder if the seal could be remanufactured in China for a reasonable cost? Our "Founding Father" Robert (Unimatic1140) has been remanufacturing smaller rubber parts, he might have some ideas for anyone looking to remanufacture a seal?