You are correct, it was a known issue, most people have replaced them more than 40 years ago/
There are no replacement triggers for it anymore. I have the same rifle, which I retired 20 years ago. Keeping mine original. Trigger is intact.
You might find a an old Canjar, but its extremely rare. Tminey used to have one, but not in a few decades.
The only solution is to send it to Weatherby, they will replace the bolt sleeve if they still have it, and install a more modern triger.