When searching for some other thing I stumbled upon this multiple. Something was wrong. I had to look several times but then I spotted it. The first k60k hand stamps was applied upside down. This is quite rare for this type of overprint. Its much more common within the later framed and unframed Z overprints.
Enjoy!
When it is the first overprint on a pane or block cut from a pane, inverts are not so unexpected. Some clerks applied the first strike in the margin to make sure they had the stemple the right way up. Others were more careless and just checked the first strike before continuing across the sheet. An odd invert in the middle of a block or pane is much more suspicious as the clerks would generally complete a sheet before taking a coffee break having laid aside the stempel.