Geo-referencing historical topographical in ArcMap using the original grid

Question

I am trying to geo-reference a series of maps of the German Military service in ArcMap or ArcGIS Pro using the coordinate grid (in red) provided by the German Military during the WWII. The attached map is an example of the maps (125 in total) which I would like to digitize. While I have some experience in geo-referencing maps, it is the first time I am using an original grid of the map to do so.

As far as I understood so far, in order to enter the coordinates displayed on the map. I should first understand the original georeferencing system. However, unfortunately so far I have not been able to find its history.

Are there perhaps other correct methods to digitize these maps?

How would you go about digitizing these maps?

Answer 1

At the bottom right there's some red text. In the corner it tells you how to read coordinates off the map (basically its an early UTM) while a bit to the left it tells you, also in red, that the red grid is the "Deutsches Heeresgitter" centered around 27° E (it's based on the Bessel ellipsoid, similar to DHDN, but older). In black above this it says, that the black grid is the "turkish Bonnesche grid" (never heard of this one).

So either you do some research on one of these, or you use the degrees which are noted at the map borders - depending on how exact you would need the digitalisation to be.