I could use some advise trying to understand where a problem could arise...
I encountered an inconsistency georeferencing maps of the Macedonia. I am using the MGI Balkan 7 coordinate system. Although the coordinates of the scanned maps and Arcmap match perfectly, the geographic location of features on the scanned maps and the ESRI world topographic map do not align, but are shifted by roughly 500m East-West! As an example just compare the country borders on the image below.
This problem arises in all the maps I have for this area. Normally I use the ESRI world topographic map as base layer to georeference to - it is my Bible. But could it be that in some coordinate systems this base layer is not displayed correctly? Any ideas on where this problem could arise and on what I can take as the 'true' location of any geographic position would be most welcome.