[ChristianK]

Thank you Dennis,

this helps very much indeed. It seems I just learned a new variant of Werknummer application. Maybe this even was a special habit of exactly this repair facility in Auxerre you mentioned. The scenery on the photos of this plane didn't look like Rechlin anyway. On the other photo you can see an armed guard right in front of the hangars. Looks like an airfield in an occupied country to me.

Thanks again,
Christian