Damn. Correct.no, he's not. it's an "SBS"
ATF 5300.11 Section IV: NFA firearms classified as curios or relics, still subject to the provisions of 26 U.S.C. Chapter 53, the National Firearms Act, and 18 U.S.C. Chapter 44, the Gun Control Act of 1968.
Marble's Game Getter firearms, with combination cal.’s .44 or .410 gauge smooth bore and cal. .22 barrels, both first and second Models, with barrel lengths of less than 18", mfd. by the Marble Arms Corporation of Gladstone, MI, prior to 1943.