Abstract: A lock mechanism includes a lock housing having an upper surface with a pair of opposing L-shaped ears, a lower surface with a pair of opposing L-shaped ears, and a front surface with an orifice therethrough. A lock plug cylinder has a face with a key slot therethrough, the lock plug cylinder received within the lock housing through the orifice in the front face. A mounting bracket has a front face with an orifice, a pair of laterally disposed flanges projecting from the front face, and a pair of retaining flanges projecting substantially perpendicularly from the front face. The lock housing is received between the retaining flanges in such a way as to have the retaining flanges received by respective upper and lower opposing ears.