You’ve got your work cut out for you Mike.

I’d start with all the Major Auction Houses that post Factory Letters on their websites included with the sale of the relevant gun of course, before you pursue the various gun sites that openly photo and post Factory letters ( for sale!). With the matching gun of course. I’m not sure they would want to participate? Daunting task.

Then you would have to address all of those violators who dare to make copies of their factory letters and sell them with the matching gun as an extra copy? Another daunting task.

Realistically though it’s great for business! Posting factory letters is free publicity for the Historical Foundation. Generates interest and in my opinion it stimulates business! The desire to obtain a factory historical letter is a win/win for all of us.

Oh and the reference you posted unfortunately is obsolete. When you are published you receive updates regarding copyright issues and the Supreme Court just screwed over authors regarding copyright so you might want to refer to a more updated reference.
Who knows though, tomorrow things might change yet again. Sort of like gun laws in California. You have to read them hourly to stay up to date!

Murph