This is a M32B1 Sherman TRV, a Tank Recovery Vehicle or “Retriever” based on the Sherman M4A1 (cast hull). The M32B1 TRV series were produced from early 1943 to September 1944 and this is one of the earlier TRVs that still exist. The M32B1 armament was an 81mm M1 mortar with 30 rounds and as secondary weaponry it had two .30cal (7.62mm) MGs and one .50cal (12.7mm) MG. The 29ton vehicle was powered by a 400-460hp Continental R974 C4, 9 cylinder engine.