I like the old ones that even have a mailing form you send in a check and they mail you your weapon:
there was even one from 1950s for a ski-mounted 20 mm Lahti or something..!
A little catalog going back to the 50s carried the Lahti complete with skis. The cataLOG was called “YE OLD HUNTER”. the 20mm rounds were 2.50 each.
The Lahti features in John Ross' Unintended Consequences.