ANY IDEA WHAT THIS IS?

[sdnlsn]

Anyone have any ideas what this is?

The only marking are "1203 J.D & S Patent 10"

Thank you for your assistance.

[wastingtime101]

@sdnlsn 
JAMES DIXON & SONS 10 BORE ROLL CRIMP TOOL

Edit: Here's a similar one listed on eBay:
https://www.ebay.com/itm/265173394826

[my-cottage-books-and-antiques]

shotgun shell reloader

[my-cottage-books-and-antiques]

James Dixon & Sons

[ittybitnot]

From a Google Lens search: 

https://www.gunsinternational.com/guns-for-sale-online/parts-ammo-accessories/reloading-equipment-an...