iriegnome, I pulled the bass out of the case to look at it quick this morning. The Frankenstein face is not really visible, unless he's grown a really thick uni-brow. I think it was just the light and the angle when I took that photo. The grain has a bit of that prismatic thing going on, so what angle one looks at it from, and what angle light hits it from can have an effect. The ET face is kinda visible, if you use a little imagination.
The comment that I did get from one guy who I showed the bass to right after I got it, and he played a few notes, yanking the strings really hard to compensate for the fact that it wasn't plugged in, was "Geez the strings buzz really bad on this thing!". The bridge saddles each allow height adjustment, and I set it up to be nice and low, and I have heavy gauge bass strings on it. With my more moderate playing technique, it never buzzes.
The thing I've always found interesting about the grain of the pieces of koa used for the body sides (I think that is koa anyway) is the fact they used pieces with knots in them. You can see one in the area near the tone control, and another larger one in the area they sculpted for the player's right arm to rest on. You can see in the photos, lighter looking lines going through those knots. Those are actual cracks in the wood. And the finish does not smoothly go over them, those are lower than the surface of the body.
I've got a Carvin guitar made entirely of koa, and they selected pieces with no knots.
As for the pieces of wood down the center of the body, I'm guessing the light color strips are maple. I'm not real sure what kind of wood the two wider, reddish strips in the center are. The grain looks like mahogany. They might be mahogany, but they look a little more red than mahogany usually looks.
What I know about the bass is largely what I've read in this thread and a few other places on the internet, just doing a google search on Bassstar. I remember ads in the guitar mags for the Black knife necks/guitars. I may have seen an ad for Bassstar back then, but that was over 30 years ago. I have an issue or two of Guitar Player magazine from 1984 and 1985 on my book shelf. I should thumb through those sometime and see if there are any ads for Bassstar basses in those issues.
I'd guess the bass's build date had to be in the 70's. The old logo on the EMG pickup (they'd switched to the small gold or silver letters in the corner of the pickup cover by the time I started reading guitar mags/ads around 1978), the brass strap knobs (see photo), as well as the brass nut, brass neck plate, and brass control cavity cover, as well as the natural finish over multi-laminated wood strongly suggest (scream, actually) 1970's.
Skimming this thread and other places on the net, I read that the early Modulus neck were deeper. Mine certainly has the deep neck profile. Quite different from my other basses.
A friend of mine who used to work at a local guitar shop many years ago says they had a couple of these basses at the shop back then.