There are 5 Ayres S2R-R1820 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 1981 and 1989.
N751WC
1989 Ayres Corporation S2R-R1820
Gann Valley, SD
N1663S
1981 Ayres Corporation S2R-R1820
Maddock, ND
N4025P
1981 Ayres Corporation S2R-R1820
Leipsic, OH
N510DK
1981 Ayres Corporation S2R-R1820
Crystal, ND
N2530B
Ayres Corporation S2R-R1820
Bannister, MI