Muscle Up a Little Closer (1957)

Joes girlfriend discovers her diamond ring is missing

Joe is engaged but can't get married until he recovers the engagement ring which has disappeared. The stooges suspect the ring was stolen by Elmo, a beefy bully, who works at the same factory they do. They confront Elmo in the company gym, but he's too tough for them. Fortunately Joe's girl is even tougher, and she gets Elmo to confess and return the ring.