I have a silver Oklad from 1817. Nibus and Oklad are completely hallmarked.
The city hallmark is Moscow. The examiner for I.B would probably have to be Ivan Ivanovich Vikhlyaev. This also fits with time. This probably checked until 1818. What I couldn't find out is the master for K.I
Maybe the experts know more ;)
Greetings
Marcel





