The M75 was in service from 1952 into the late 80s.   Towards the end of WW2 the military saw the need for a squad sized transport vehicle.  Its predecessor the very large M44 / T16 was designed for over 25 people and was difficult to maneuver due to its massive size.  In 1946 the development of the T18 started. It was based on the chassis of the T43 cargo carrier.  It received many changes over its 6 years of development before landing the designation T18E1 and was ordered into production in 1952 as the M75. 

M75 APC model includes 7 pieces in total.  Body, Cupola, MG, 2x fuel tanks, and x2 Tracks.