From my article (see here): The overprinting was done in letterpress technique with a small, manually operated, printing machine called “Trigerica”. Five-pointed stars were cut out from the linoleum strip in horizontal setting (10x1) while inscriptions were composed of the lead letters. Overprints were done row by row, all five rows until complete half-sheet of 50 was overprinted. For some values - "Famous women" and Porto - smaller pieces were used. Overprints were done in multiple phases: first five-pointed star in red color and then on top of it text in black color.
1944 Senta local provisional issue, proof sheet. Certificate Veličković. Very rare.
Since stars were carved in linoleum strip by hand, they are not of ideal form nor are identical to each other. The first star is different from the second, the second from the third and so on. Also, note that the relative position between star and text is not constant and that each phase of each row has its own shift and rotation.