I'm no Fender expert, but the 4001 is authentic, and in quite good condition for a (formerly) white Rick. The white finish seemed to be more fragile than most colors and is usually chipped.flaked/scraped off in a lot of places.
I would want to see a pic of the edge of the fingerboard near the nut and the ends of the truss rods to be safe if I were interested in it.
Here is a site to help you know what to look for: http://joeysbassnotes.com/
The serial number makes it an April 1979 build.
It should sell in the $1500 range, maybe a little higher since it's an uncommon color and in relatively good condition.
If it goes for less, it's a good deal.