QUESTION: Are there any physical coin creators that would be willing to contribute to the process of creating a physical collectible where they would create a portion of the key in a multi-sig coin that would collaborate with other physical coin creators?
Requirement: At least 3 known and trusted physical coin creators would be needed to do a 2-of-3 multi-sig coin.
I can see why those who turned me down in 2014-2015 did not want to participate or just never got back to me. I'm also not 100% sure I would want to do such an endeavor as it would depend upon the terms & agreement and the outlined responsibilities of each party
Sounds like a lot of work.

Good in theory... but now you are trusting 3 makers
And the logistics of this sound horrible
How about just let makers make their collectibles however they want.... keyed, keyless, DIY, whatever....
It just comes down to if you trust the maker... if not... don't buy the collectible