Trying to calibrate scanned Kompass map K617. Maps shows UTM grid (red) + geographical coordinates (blue). Datum is said to be International (red) and European 1950 (blue).
After calibrating the map I notice that TTQW's grid in UTM always overlaps with the red map's UTM grid, but has a shift from the geo blue coordinated.
What is the reason of the shift?
What are the best settings to use for calibrating Kompass maps?