I am trying to georeference an old map of the German Reich from 1930's. The map is based on the topographische Übersichtskarte des Deutschen Reiches 1:200000.
The coordinates depicted on the map, that I want to use to georeference it, use the Ferro Meridian. I know that the original map uses a conic projection (German: Schnittkegelprojektion) with two parallels at 50° and 53°. Axis of the cone is the same as the axis of the earth. I don't know anything about the central meridian other than that the angle between the central meridian and the corner/border meridians (German: Randmeridiane, do not exactly know the translation) is 0°23'28''5.
The issue is to find a suitable projection, which fits ok and at the same time allows me to input the coordinates in Ferro using ArcMap as the geoereferencing tool.