The listing, USA #1759 1978 Viking Mission to Mars, mint has ended.
USA stamp commemorating the Viking Mission to Mars
Year: 1978
Catalog # 1759
Condition: full gum, mint never hinged, post office fresh
I have several of these stamps, all identical, the scan is representative of what you will receive.
My general terms for stamp-related Listia lots can be found here (please read, it answers a lot of basic questions):
http://listiarules.webs.com/