Marlin offered the 410 as a Free-Be gift if you bought 4 stock shares at the time. This was one of Frank Kenna's ideas to additional raise money to help payoff the $1million debt he accepted when he bought the company at a Sheriffs auction in 1921 I believe it was.
Marlin had gone backrupt after WW1, The orig Marlin family ownership was gone and it had gone thru a change to Marlin/Rockwell Co etc.
The stock shares were $25 at time I believe. Buy 4, get the free shotgun.
Another offer was buy 4 shares and get a 5th share free.
Several other Marlin firearms were in the Free-Gun/for stock shares offer as well. One was one of the many Hammer Pump shotguns models (Model 17?)
The 410 Lever was a retail offering at the time as well as were the other guns in the stock offering/free gun.
They were not set aside just for those buying the stock shares and opting to recv the 410 Lever (or any of the others) as the Free Gun.
They were listed on dealer/retail price lists of the time as well as in the MArlin Catalogs.
AFAIK the 410 was in 2 1/2" chamber only.
They did make some in a Deluxe version. Slightly better qual wood and checkered.
Some factory engraved specimens may be out there as about anything could be ordered.
But most collectors will be very wary of any brought forth. It's hard to believe much of anything you see anymore.