Although there were other flight sets,[a recent commemoratives in L.V. honoring the USAF's 50th Anniversary] I believe you are referring to the Flight for Freedom Series which Steve Cutler arranged as part of his contract with the Flamingo hotels in Laughlin and Reno to house his Nevada Gold Museum. Unfortunately, just months after the dedication of it in Laughlin, the museum closed and is looking for a new lcoateion.

In any event, the series caries N codes from N9720 to N9731 and was issued by the Reno Flamingo Hilton. They are given a D rating by TCR. Thos of us on Steve's subscription list paid $66 for each of the 9 setes that were issued at the two casinos.