It is much more common to have 1945 Mostar stamp with a slightly shifted overprint than the ideally centered one. The reason for this is because the clichés where mounted too narrow horizontally and also because stamps with different heights were used for overprinting. So, displacements of less than 10 mm are common, whereas shifts larger than 10 mm could be quite attractive and highly valued, especially those on larger pieces. Read more: Mostar Provisional Issue DFJ 1945 - Contribution to the Study of Overprints.
1945 Mostar local provisional issue, 10 / 2 Kn on pelure paper, vertical strip, positions 64/74/84/94, overprint shift at dx=12 mm.