Hello!
I think I can't interpret better, then the mentioned citation. So if the item didn't meet the standards (silver:750‰ ;800‰ ;900‰ ;950‰ ), punched this mark to the item -with the control mark.
Here is an example for you.
Before 1867 in the Monarchy the fineness standards wan in lot. From 1867 the fineness measured in metric system. 13 lot was equal 812,5‰ . The items, which made in the old fineness, get this punch with the control mark. (In our example R1 - Eperjes, now Presov in Slovakia).
My opinion: Your item made a little before 1868 with a little diverse fineness, then the standards was. And I think, the maker (and his guild) didn't punched the old marks, and the assay office punched the storage mark. I think, somewhere in your item have to be a little controll mark.
I hope, now clear. (sorry, my english is pure..)
Best regards!
Krisztián