Origin of eastern Germany town marks

[Solpar]

Below marks of several lancet spoons made around 1830-50. The marks (also one similar items) are pretty small and can be found on the back close the stem's end.

Do these marks originate from
a) Dessau
b) Zittau
c) Erfurt
d) Halle
Who are the makers? Any literature known?

Thanks,
Solpar

a)
b)
c)
d)