Mary's map at scale 1:100,000 would be this map (Hanover N4). http://www.lib.utexas.edu/maps/ams/central_europe/txu-pclmaps-oclc-6624264-hannover-n4.jpg We can do some tests to see how far off the co-ordinate translator might be. Point 56 15 (rX560150) intersects directly on a canal on the Hannover N4 Map. It is slightly left of the road that runs south from Evern and crosses the canal. The co-ordinate translator puts the location about 200 m north of the canal and to the right of the road that runs down from Evern (maybe 200 m further east of the the N4 map point). So a straight line error of around 280 m. Update: on the co-ordinates translator page here: http://www.echodelta.net/mbs/eng-translator.php is the following statement. (It appears they did some tests similar to what I am doing and got very similar results.) "Its imprecision, evaluated on the basis of a series of "gauged" points, varies from 5 to 30 arc-seconds, depending on the map projection used (this corresponds to an imprecision varying from 150 to 1000 meters on the field)."