Help with identifying unknown Epiphone bass

Hi guys, I need some help identifying this Epiphone bass. I was kind of reluctant to post it here at first since it could be a killer bass at an unbelievable price (and all you bass lovers would snag it up in seconds), or it could be a horrible waste of money, which I would have suffered greatly from.

Heres the link:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2517870924

I've emailed the seller and he says it's about 20 years or so old and can't locate the serial number, but has found prints on the neck plate stating "Steel Neck Adjstable Made In Japan". I've checked with Epiphone's website and their blue book file, and it stated that the Epi basses made in Japan were always stamped with iffy serials, so there wasn't a really sure fire way of knowing where and when it was produced. I've asked one their forum about it and a certain Bob was kind enough to help me out. He thinks the bass was from the 70's, but isn't too familiar with Epi's basses from that era.

To me, the bass looks very similar to all of the MIJ Epi guitars that were made in the 70s/80s, but I've never seen a bass like this. I've searched the net and there's next to nothing on this bass. It could be a hacked frankenbass of some sort or it could be some lost relic of fine electric bass craftsmenship.

If any here has any info or comments on old epiphone basses, I would really appreciate 'em.

Thanks in advance,
Mak