About 8.25" x 11.5". From September 1929.
This appeared at the end of the silent motion picture era when Tom Mix was wildly popular. Mix is shown in a macho pose wearing a Buckskein shirt, while on his horse, with a western-themed movie scene in the background. Tom Mix was a major endorser for Buckskein (among many other products), but was soon replaced by the Eskimo-looking Buckskein Joe when the talking pictures began in 1930. It's from the back cover, so it's slightly soiled, as shown.
Inside back cover is the standard Marble Arms cleaning supplies advertisement variations of which appeared for many years, and includes jointed rifle and shotgun rods, nitro solvent, and rifle rope (Webster Marble's early rendition of today's "Bore Snake").
The star of this page is clearly Tom Mix.
Overstamp will not appear on your ad. Shipping is $4.95 USPS First Class in a self-displaying resealable archival sleeve with acid free backing board, sent in stiff photo mailer with tracking to USA ONLY.
I'm happy to ship additional ads in the same package at no extra charge. If you purchase more than one ad, add them to your cart and contact me and I will send you a combined invoice with the discounted shipping amount. Sorry, no foreign sales.