I don't actually possess this quite yet, but it's on it's way to me. 

  I'm thinking Zebrawood (?) top, Mahogany body? 

Could be a tulipwood top. Nice!

Wow.  Someday I'll own a fretless.  Beautiful - congrats!

Hmm. Interesting. I think you may be onto something. Here are more detailed grain shots:  
[img">http://club.alembicguitars.net/Images/394/227748.jpg[/img]
  and  

  Very close match in appearance to http://club.alembicguitars.net/Images/411/25360.html?1142879257] this Tulipwood Essence.  Thanks!

Hello Tom, congratulations lovely looking bass.
For me the Essence body shape is very comfortable to play also.....
I think you have too many numbers in the serial.
 
slawie
 
(Message edited by slawie on April 07, 2016)

Thanks, Slawie
 
 I think you have too many numbers in the serial.  
 
Yeah, I noticed that after posting. Unfortunately that's the number reported by the seller. When the bass arrives tomorrow, I will post the corrected serial number.

Fortunately the previous owner had a pic of the actual Serial Number. It looks like the correct SN is 98K 11252 USA:
 
 
 
Moderators, can you please change the subject of this thread to 98K 11252 USA ?

Hi Tom,

Adriaan was correct - it's Tulipwood (a type of Rosewood). Here's the rest of the details:

model name: Essence
model number: KLB5
top: Tulipwood
accent: Maple pinstripe
body: Mahogany
neck: 5-piece Maple with 4 Walnut pinstripes
scale: 34" long
fingerboard: Ebony, unlined fretless
side position markers: Bronze dots
hardware: Chrome plated
pickups: Alembic MXY56
controls: volume, pan, filter, mono output
originally made for: Guitar Center, Chicago
birthday: January 9, 1998

It's not recorded as a custom order, but surely it must have been.