Karl, no reason to spend a lot of money. It's just a piece of rubber. Does not even have to be in a "U" shape. Find a piece and sandwich/bolt it in between trans and metal bracket. Does not have to be vulcanized to the metal bracket does it?
Also that "U" shape was used for many years beyond 1941. Not sure if dimensions are the same but maybe close enough. Cut rubber off of a transmission mount/motor mount. Plenty of rubber mounts used on Volvos smile

Example
Shipping from USA is very high. Sweden now charging import VAT.....cut up a tire and use it. Any flat rubber piece. This is not high tech.

Ebay

Looking at available replacements, I am suspicious that your mount has had it's rubber replaced from something else.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn