Unfortunately, you're looking in the wrong place for this kind of info. You might try some of the airgun specific forums, or "Jim E", a frequent seller of German target air rifles. He's been mentioned repeatedly on several boards: Gateway to Airguns, the "Yellow" air rifle forum, and on "TargetTalk".
Get that puppy running right, and you'll have a very sweet shooting rifle.
Scott
P.S. - I couldn't help myself: See what "Jim E" had to say about the LG90:
http://targettalk.org/viewtopic.php?t=11447
