Two years ago (maybe more) Sage Crusher ordered a large amount of rubbers from a person overseas. I was in on that order, I'm sure it was a PIA for Sage but the rubbers work great.....maybe worth reaching out to them again.
I bought 7 sets from Gulfi also.
I had to have my sister pick them up in sweden when she was driving through the town.
It worked out good though.
I sold my sled with them installed. (Sold to local folks and used on snowbikes also.)
They work great.