I am currently working on mounting the stamps of Tunisia and came across this stamp with 2 different sized printed images.
Both stamps are perf 12.5.
The stamp in front, in the picture, measures 21.75mm (approx) top to bottom, while the stamp behind it only measures 20mm.
At first I thought they might be 2 different issues, but my catalog gives no indication of any other issues other than #138.
Maybe it says something about them in a YT catalog? I just don't own any other references yet. Ideas?