There are 4 Aermacchi AM3-C 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 1973 and 1974.
N7091K
1974 Aermacchi AM3-C
Bellingham, WA
N955ZA
1974 Aermacchi AM3-C
Casper, WY
N8ME
1973 Aermacchi AM3-C
New Castle, DE
N949CM
Aermacchi AM3-C
Oro Valley, AZ