Hi Wacko Hatrack,
Pretty bass machine you have there! Just thought I'd let you know, your bass is a 1973 Guild
JS-II bass. The Jetstar models that Guild made were sort of the mid-to-late 60's predecessors of the
JS basses and looked like this:
http://www.oliviasvintageguitars.com...urst%20002.JPG
Here's a dating resource for Guild guitars and basses:
http://www.guildguitars.com/index.php/support/dating/
Also, the pickups in your bass are in fact not Dark Stars. They are the stock Guild humbuckers that came standard in Guild basses starting around 1971 -- very different from Dark Stars (which are single coils), physically and tonally.
I'm guessing by "first generation" you're referring to the original Hagstrom Bisonic pickups that Dark Star pickups are based on? These were found in Guild basses from 1965-1971, at which point they were discontinued. Here's a link to the Dark Star website which has plenty of info and pictures. The original Bisonic pickups looked identical to modern Dark Stars.
www.basspickup.com
Hope this info clears some stuff up. Good luck on your sale!