Who is the maker?

[niceguy1]

Hi

Who Is the maker & what’s the tiny mark on the right? They are not the clearest & difficult to photograph.

Thanks

[AG2012]

Hi,
Greek letter Delta for Moscow assay office.
МЮ5 - Московская ювелирно-часовая фабрика (Moscow jewelry and watch factory), 1955

Regards

[Goldstein]

Hi -

a very common often seen pattern:




Regards
Goldstein

[niceguy1]

Thanks for the help.