Is it not stamped into the end of the tuning head? Look and see it should be there.
 
OO

Looks like koa to me. Tasty!

If it's an 81, the serial number could be stamped on the fingerboard between the last fret and the truss rod cover.  Look close as I have one that has almost disappeared.

Yep, spectacular koa top. Man, I just love figured koa. I think it's my favorite.
I'll bet the s/n is at the end of the fretboard too.

So, the serial number is worn off the wood and I'll be seeing if I can retrieve it.  Was in touch with Mica today to find out about restoration and will be sending the bass to Alembic shortly - very excited to restore the bass and use it playing out. Thanks to everyone for their suggestions. Just read every Series I FAQ and learned more than I have in a long time - this is a wonderful and helpful community.  Thanks again, Todd

That certainly does look like tasty Koa.
Again, congratulations Todd.
Mike

That last picture looks very nice!

man what a beautiful looking older series one!! i love koa.

Very nice. I'm tempted to believe the koa was cut from the same log as one of my '82s. The figuring is almost identical, judging by your picture.

I'd love to see a picture of your Koa series bass.  I was able to make out the year 82 at the bass of the fretboard.  I haven't posted pictures of the back but will tonight - it also has a great grain pattern.

Chances are that you can also find the serial number stamped in the wood under the pickups.  
Been there, done that!
 
Wilfred