There are 3 Mckinnon G21G aircraft on the U.S. registry that TailWiki has a page for. Every one is built from the public FAA record — year, serial, engine, home base, and registration history — and owners and pilots add photos, trips, and stories on top. The ones listed here were built between 1944 and 1970.
N70AL
1970 Mckinnon G21G
West Bloomfield, MI
N221AG
1944 Mckinnon G21G
Addison, TX
N77AQ
Mckinnon G21G
Livingston, MT