I have embedded your images.
It is Georg Roth of Hanau.He is known to have produced renaissance revival serving forks and spoons.
(No dimensions and weight of your fork is given, though).
There are no fineness marks on most of Hanau silver.It can be anything from .800 to .935.
For example,Berthold Müller (Chester and London) imported Hanau silver to Britain,Georg Roth included, and of course it had to be sterling or higher fineness.
So, your item is solid silver but of undetermined fineness.