Hi Paul,
Well, I'm not much good with advice for used values, as I only sell the new ones, and we don't track details relating to rarity like how many Zebrawood Spoiler Exploiters were made in 1983, but I can tell you the record of what materials we made the bass from:
serial number: 83S2895
model name: Spoiler Exploiter
model number: SMB4X
top: Zebrawood
accent: none
body: Mahogany
neck: 3-piece Maple
scale: 32 medium
fingerboard: Ebony
inlays: Pearloid (plastic) ovlas
pickups: AXY4
controls: SB-1 volume, filter, Q-switch, mono output
originally made for: Midwest Music, OH
birthday: October 3, 1983