Manufactured by Michael J. Barrett, who is best known for his 1/2 scale replicas of Winchester rifles. According to an included framed letter, this .22 LR chambered M1928A1 Thompson style prototype rifle was designed by Barrett under contract for Marlin Firearms. However, before the rifle was completed Marlin canceled the contract. Despite that, Barrett completed this prototype rifle as the only example of its kind manufactured. With all metal surfaces left bright, it mimics several features of the M1928A1 Thompson sub-machine gun, including the sights (fixed brass bead blade and peep rear), Cutts style compensator, charging handle, and furniture. The receiver is laser engraved "MARLIN/NEW HAVEN, CONN. U.S.A." on the right side and "EXPT/FOR/MARLIN/NO. 001" on the underside ahead of the magazine well, along with Barrett's personal mark "MB." The barrel was cut and modified from a Remington Model 550-1, with the original roll marks visible under the forend. The action is fed from a 25 round rotary magazine, which is secured via a set screw and requires the action to be partially separated and the bolt held back to remove. To fire, a round button on the right side of the lower frame must be depressed in order to release the striker, serving as an unusual sort of grip safety. A truly one of a kind Marlin prototype rifle that bears a strong resemblance to the larger Thompson machine gun it was modeled after, along with novel features of its own.

Excellent overall for a experimental prototype left bright, with light handling marks, tooling marks, and some light spotting. Mechanically excellent. Arguably one of the scarcest Marlin firearms ever offered.