This fork was made by unknow maker "ИЦ". I think this maker from Odessa. 1914.
Соломон Гробдрук (Solomon Grobdruk) - was jewelery dealer. Perhaps he from Kishinev.
Information about Frolov and Ushatov is correct.
AG2012 wrote:The assayer MK was Mihail Karinsky PL 1165 and 1166.
In office 1825 - 1838.
Qrt.S wrote:In addition, most likely the customs brought it there. In other words an imported object.
AG2012 wrote:......But, were the measurements so precise at the time ?