I'd say the one on e-Bay
is a 1980's model. The newer MIK basses have a different headstock (with "Handcrafted in Korea" and a s/n on the back) and a metal jack plate (vs. the plastic one on the `80's models).
All of the 1980's Blues Kings that I've seen have had one of two different headstocks: a "Tele-style" (like the one on e-Bay and in
this article) or what I think of as an "ESP-style" (like my 1984 model, below, right).
The headstock logo on the e-Bay bass also matches both mine and the one in the article.
I'm not sure when or why St. Blues switched headstock styles. My bass's s/n is 038XX and it has the older, ESP-style headstock. The e-Bay bass is s/n 05545 and it has the Tele-style headstock, as does the bass in the article, s/n 35304.
The nut on mine is about 1.635" (IIRC), with a very comfortable neck. Definitely
not baseball bat territory. Not surprisingly, it reminds me a lot of the neck on my 1980's ESP 400 series P/J.
Knowing what I do about these basses, if I didn't already have one, I'd snap it up. They're really a great blend of Japanese and American workmanship. $650.00 is a decent price right now and they don't come on the market very often. If you like passive P/J's, I don't think you'll be disappointed.
P.S. As far as I can tell, the bass in the Craigslist ad linked above is one of the newer ones, but with aftermarket pups and bridge. Beyond that, it's hard to tell...