St.Petersburg maker's mark?

[Atlas]

Hi,
Help would be appreciated with identifying the St.Petersburg maker's mark in the picture if you please?


Regards,
- Atlas -

[Qrt.S]

This is purely a guess:
Johan Björqvist (JB?) was born 1806 in Hamina in Finland. He arrived to St Petersburg 1818 and became journeyman 1823 and master 1849. It is known that he was still working in the 1870thies. The hallmark is punched 1878 by Ivan Yestigneyev (1870-1894) making it possible that the maker could be Johan Björkqvist, but....? Unfortunately I don't have in my records any picture of Björkqvist's maker's mark.

Any better suggestions would be appreciated...

[Qrt.S]

Ahhh! I made a typo . The name is Björkqvist of course, sorry.