Designed to meet the same requirement for a fast combined dive/torpedo bomber as the Douglas Skyraider, Martin's "Able Mable" (or "awful Monster") was a considerably larger and more powerful aircraft than its "Able Dog" competitor, being powered by the colossal Pratt & Whitney R-4360 Wasp Major. The original USN order for 750 aircraft was predictably pared after V-J Day, and although the Mauler was to enter service in 1948, the AM-1 would enjoy none of the Skyraider's longetivity.
The AM-1 could carry more ordnance than the Skyraider - one aircraft set a record in the spring of 1949 by taking 10,648lbs aloft - but the AD was simpler to maintain, easier to fly, and did not take up as much room on carrier decks. Thus, the Mauler was rather quickly relegated to Reserve units, and then out of service entirely by 1953.
Review of the 1/72 AM-1 kit from Siga Model Scale Aviation Modeller International February 2003 p.117