Deutsches Reich 1921 'Reaper' Question

Afternoon all, first post for a while, find I need a little help!
While sorting a recently purchased old collection I came across a variety that neither of my German catalogues, Stanley Gibbons (2007) or Michel Specialised (2011), give a mention.
It is on a 1921 'Reaper', value 160pf, watermark lozenges.
SG number in my catalogue is SG165, in my Michel it is MI170.
If you look at the figure on the left, there is an un-shaded area on his chest, next to his arm. I have seen the Michel listed 'open shirt' flaw on the 40pf but that is a different flaw which affects the main figure in the centre. None of my other 'reapers' show a similar lack of shading. Has anyone seen another example of this anomaly on the 160pf, or indeed on any of the other values?
Thanks in advance for any help.

Hello all,
Just a gentle 'bump' for my thread from the other week, in case anyone has any ideas?
Thanks in advance.
DavidR

DavidR,

Sorry. I missed this thread the first time around.

I haven't seen that particular flaw before, and it's not listed in Michel or Verlag's more detailed plate flaw catalog for these issues. It's possible you have a previously undocumented plate flaw, or it's not recognized as one because it's a one-off under-inking rather than a consistent plate flaw.

Thanks for your response PostmasterGS, I suppose it is just a 'one-off' as it hasn't already been found, but time will tell! I will include your comments on a note alongside it. Hadn't heard of the Verlag catalogue before, so I will keep an eye open for a copy.
Thanks again.

DavidR,

My mistake. It's not Verlag, it's Schantl -- technically Thomas Schantl Verlag (Thomas Schantl Publishers). I think the current version is the 4th Edition. Looks like this.

Michel also publishes a plate flaw catalog, but it's just a compilation of the info already shown in the Specialized Catalog.

Thanks again PostmasterGS! Useful link!