I agree a great resource. Here are two others, unfortunately not available on the internet.
"Spirit of the Times", Published in N.Y. I was fortunate in picking up copies from 1879. The ads are fabulous,for example Ballard, Remington, Parker,and most of the great gun and ammo; dealers of the day are covered.[My source Maine antique shop.]
The best resource that I have located covering the English gun trade in the 1920,s and 30,s; is the magazine,"Game and Gun."The editor for many years was; Major Sir Gerald Burrard,of Shotgun fame. I am fortunate to own bound annual editions of this magazine 1925-1931. The information, ads and articles in these magazines is not to my knowledge found in any other publication.[ There is acopy for the year 1925 posted at present on ebay].
These publications are hard to find, mine came from a second hand antiquarian book store.
