Austrian silver teaspoon, Steyr 1840's

[Sebastian]

I am looking for the maker of this 13-lotig silver teaspoon, one of a set. Does someone recognise this maker, or know where I can look for it?
It is marked with the assay mark for Steyr, a sub-office of Linz, in Upper Austria (G1), sometime in the 1840's.The maker's mark is a monogram of script letters inside a shield, maybe Gk. I have seen similar shaped maker's marks in Waltraud Neuwirth's books on Vienna silver of the first half of the 19th century.


Can you please help?