This is going to be a daunting task then. For instance, I've used a lot of collages to illustrate specific points in the text....6-12 guns in each. I'll have to go back to each auction house for each gun in the collage. And some of the ads on for instance Guntrader.UK whose pictures I used no longer exist...I copied the text of the ad but not who posted it:
And what about press articles? Much of this history was built around an analysis of press articles and advertisements, (Much like the biography of James Madison or John Adams relied on their letters). I mostly used this site: Since I paid for a subscription they may be amenable to my using extracts but I'll query them to make sure:https://www.britishnewspaperarchive.co.uk/
I notice in John Cambell's beautifully laid out article on Reilly in "Double Gun Journal" in Summer 2015, "E.M. Reilly, Purdey's Pretentious Rival," he used numerous advertisements and pictures from the internet (I collected many of the same pictures long before I know of the existence of this article). Perhaps Joanna or Daniel Cote might advise how they handled this.
A publisher would do this for an author. Perhaps I'll give that a try as well. If anyone has leads as to who publishes gun books (Larry Brown?), would much appreciate names.