It most likely used the David Lowe STC, which basically says 'Remove Cessna 150 gear (part numbers), install Cessna 140 gear (part numbers) and tailwheel, using Cessna 140 parts.' I've heard it's renamed a "Cessna 140C" instead of Cessna 150 after the conversion, but not sure if that is accurate or not. It's only applicable on fastback 150's.
Jacob
