Sometimes, I go on Racingplanet.com. The US version is the same as UK site. Pick you're scooter, then choose OEM parts. There, it shows all parts in graphics with part numbers within each part group. If the part matches, all good. I have looked at other bike models, for parts and have matched a few bits.
Not sure that this is of help to you, as you may seeking the specification of a part and the fact the part list below the graphics is in German, makes it harder!