Thanks guys. No date on the hub, I know was not made in Chicago (Schwinn sticker, etc on China made). The tire (good idea) is original but not a "Schwinn Unicycle" tire as too new for that. However, there is a 4 digit code in a oblong circle (similar to the DOT codes on auto tires). If that is a manf date, then was the end of 1989. So possible on a 1990 model and sat in the Showroom for a few years before sold (I know the Schwinn shop I worked in as a kid, that same one sat in the window for many years). The seller emailed me and said he was off by 10 years (math in his head slip) so mid 90's and his wife thought more towards the late 90's (moms tend to remember what age kids were when they got something better). Anyway, not an old Chicago classic, unfortunately. So I am riding it (more or less), after 50 years of never sitting on one. Forgot what a workout it is on your legs, especially old legs!!!
Again, thanks for the help!!!