Hi RK,
The VOPO Luger IS a nice-looking example for sure.
How, exactly, the author has managed to "add" 3mm in length to the 100mm and 200mm barrels is unknown to me. Even with my limited knowledge of the German language, I believe it's obvious that he's speaking of the Artillery model we know as produced by DWM and Erfurt during WW1 and not a "special" version with a 3mm longer barrel. While called an "Artillery" model, it was issued in large numbers to Machinegun units as well. That some were issued to units garrisoning stationary defensive positions - forts - isn't surprising.
Your theory that the article may have been in English first makes sense. In any event, if there's a long barreled Luger out there with an extra 3mm of barrel length, I'd like to know about it. I seriously doubt that there is but I've been wrong before. Yesterday, for one example! <img src="graemlins/c.gif" border="0" alt="[ouch]" />