Thanks for the suggestion for a substitute. I've saved the post and will use it if it becomes necessary. I prefer to leave things original but I'd rather it worked.
Are you familiar with the Hallicrafters reflector? There's a lot more action than here and you might be able to find someone with parts or a parts unit. I've found a number of knobs there.
Go to
www.qth.net , select "Email Mailing Lists" on the left. I think the process will be clear from there.
Harry