Not sure what the functionality of the piece in the back is, seems to serve no purpose.

This vintage Paymaster Check Protector X-550 Series is a must-have for collectors of antique mercantile items. The machine comes with a key, allowing for secure protection of your checks. The maker of this item is Paymaster, a well-known brand in the world of cash registers and adding machines.

This check protector is perfect for those looking to add a unique piece to their collection or for those who appreciate the intricate design and craftsmanship of vintage mercantile items. Its functionality as a check protector adds an extra layer of security to your financial documents. Add this rare item to your collection today.