Mystery Baretta

[BarettaBoy]

Hi I'm hoping for some insight into a used Baretta I just bought.

It is all period correct, and appears original.  The seller provided a copy of the original receipt, confirming that it was purchased in Winnipeg, Manitoba, at Long & McQuade, the Kramer dealer, in 1986.  It is in the original hardshell case with Kramer logo.

It has the "small logo" Floyd Rose with the screw in arm, Made in Germany.  It has the tilted banana headstock with black Schaller tuners.  It has the black stamped steel baseplate saying "KRAMER", but IT HAS NO SERIAL NUMBER.  It doesn't look like a replacement plate, either.  When the sales clerk filled out the original receipt back in 1986, he wrote "#" but then left it blank, so it looks like it didn't have a number when it was bought.  There is a note on the Vintage Kramer website with a pic of a neckplate like mine, saying "Sometimes thought to have been used on artist instruments or one-offs, the non serial plates are very uncommon".  However, the receipt from 1986 gives no indication the guitar was a one off or artist instrument.  

Also, instead of a Golden 50s or Duncan JB, it has a Schaller pickup with Allen-screw polepieces, with a sticker indicating Feb 1986.  The pickup registers a DC resistance of 13.3 k, which suggests that it is a Schaller 2-in-1, a discontinued pickup that was offered on other Kramers of the era but not the Baretta, as far as I can tell.

There's not much in the neck pocket or heel.

I'm attaching the photos in the hope that you can help me identify it.  The lack of a serial number is the biggest mystery.  Maybe it was build for a trade show, or was a prototype?  Still doesn't explain how it ended up at a dealer on the Canadian prairies.