Well, my search for this elusive animal is finally over.
I found a couple of folks who knew exactly what this beast is.
What I have been calling the German/European "DT Series" Destroyer is, in actuality, the first incarnation of the DT-420.
It was, indeed, a German only release from 1992/3 and was available with either a Cherry Sunburst finish or a Black finish.
I said "first incarnation" because the model designation "DT-420" was reused 10 years later in 2002/3 on a completely different Destroyer.
The second incarnation of the DT-420 was available in the US market and came in either a Candy Apple red or a Black Pearl finish.
Visually, the two incarnations of the DT-420 are completely different in appearance so there is no chance of mistaking one for the other.
1992 DT-420
2002 DT-420
Yes, I said "EX Series", not "X Series".
One of the same folks who identified the German DT-420 also owns an "EX Series" Destroyer.
At first glance, I was convinced someone had bolted an EX Series guitar neck on to a Destroyer body.
As it turns out, there actually was an EX Series Destroyer, model DT-320, again made exclusively for the German market and - we think - manufactured in the 1993 timeframe.
The body has a black finish and the neck is unfinished.
Unfortunately, that is about the extent of what we think we know about this rare guitar.
Update - 25 Jul 2010: the proper model designation for this is MED-320, not DT-320, and I have no idea why.
Update - 13 Aug 2010: I finally landed one with the help of several friends in Europe. It has a bolt-on neck and there is a sticker on the neck butt just outside the pocket that states, "MED320-BK". It has no-name machineheads and pups. The back covers of the machineheads and the ground plates of the pups are blank. It does, however, have an Ibanez TRS-TREM (Floyd Rose licensed) double locking trem unit and, if I'm interpreting the serial number correctly, it was manufactured in Korea (not Japan) in Oct 1993.