You mentioned the occasional civil application for the Falcon, so you know about the 14 Falcon mailplanes. While the airframe was based on the Navy Falcons, they had significant differences, namely the Liberty engine and were granted an ATC (103), so they are a legitimate civil type. Trivia: It was the last type designed to use the Liberty.
Another, for NAT had a geared Conqueror.

Also, our UK friends might be interested to know that Curtiss bought the U.S. Moth firm in 1929 and produced them under license until 1931.
It also bought Travel Air in 1929 in the pre-crash, post-Lindbergh boom.