Hello!
I believe that this is Malorossia (Kyiv, Kharkov, Chernigov, Zhitomir etc.) of the 18th - early 19th centuries. The Russian probing system was introduced in Kyiv in 1825, in Kharkov around 1835. Prior to that, a lot probing system was used there.
For example, the mark of the Kyiv maker Gerasim Protsenko (Герасим Проценко - ГП)), who worked from 1821, and a few more marks of unknown Malorossian makers.
Regards.
