Winchester .410 Dummy shells

The two shells in the center of this photo are paper dummy 3" .410 shells.
The headstamp reads; Winchester Made In USA
The word Dummy is on 2 sides of the shell and it has a rolled crimp.
I was told these were made for the Winchester employees to cycle the guns during assembly but also that they came with Model 42 pumps. The Model 42 came in 2 1/2" and I have never seen the shorter shells in dummy configuration.
I’m curious how common these are and what others know about them.

These Dummy shells are quite common and are available from any Gunsmith supply company, including Midway, USA. They are used by all gunsmiths to test and demonstrate the guns in their shops. The dummy shells come in all gauges from 10ga to .410 and the complete line of metallic rifle and pistol rounds.