I'm sure it was sitting out somewhere before they decided to sell it. You can tell it was hardly used because the paint on the frame would be more worn off from the riders' boot if it was ridden a lot. It's actually cleaner than my motorcycles were most of the time. I think it's from the mid 90s.

Horst Leitner was the founder of Amp Research and designed the suspension for Amp bicycles. He also patented his rear suspension design "Horst Link" which was purchased by Specialized and licensed to other bike makers for years. He branched out into automotive products including articulating running boards for trucks and even electronics.
Check out the fork on this bike. A friend had one bitd.