I'm sure that Gibson only made the Flying V
bass in the 1981 model year, meaning a few may have actually shipped in 1982; and that only about 300-400 were made.
Epiphone makes a copy of the 1958 Gibson Flying V guitar. They make a companion bass, and I just now realized that they call it the 1958 Flying V bass. That's obviously what you're seeing on different sites. But in fact Gibson never made a Flying V bass in 1958.
I do know a couple of guys who own 1981 Gibsons, but I don't know of any for sale right now. They occasionally pop up on eBay or gBase, an all-original might go for $1400-$1800, a modified one for less.
Here's a site you might find interesting:
http://www.flying-v.ch/ . In the Gallery section you'll find some 1981 bass photos.