Hi,
The closest info was given by Qrt.S (see above).
There was well documented Mercury export mark depicted in Tardy page 77, alongside hoopoe bird of the same period.
Then, irregular polygon mark with various initials depicted here, supporting the conclusion by Qrt.S.
Why would Klinkosch bother to apply his well known maker`s marks twice and then again JCK in irregular polygon, if the mark far left was not meant to prove the item was for export ?
That`s the only indirect proof we have, based on assumption and logic, not on any reference,though.
![Image](https://abload.de/img/worldaustria4bisx3kpm.jpg)
There is no reference when Mercury mark was replaced (if ever) with irregular polygon and initials within it.
Regards