Hi,
It was a very qualified presumption! The mark is nearly identical.
Here is the Parchim an der Elde mark reproduced in Scheffler as #502 from a church silver item from The S. Marienkirche in Parchim by Johann Heinrich MICHAEL with an engraving 1847. Scheffler also mentions a "Crowned P" #501) on a church silver piece by Michael engraved 1813.
Scheffler has listed Steinman (Steinmann) as #20, mark #517 as a Parchim silversmith, but he is not sure, the mark illustrated in his book is from a teaspoon engraved "FK 1851".
Best regards/JAKJO