Here is an example of how "complicated/difficult" it can be when looking for somebody:
A Finn Heikki Kaksonen, born 3.4.1879 in Kerimäki moved to St. Petersburg 1893 and worked as a journeyman with a Finnish master, Pekka J. Silventoinen (P#1826-27). Kaksonen became master in 1913(-1918). It is known that he owned a workshop in St. Petersburg 1913-1918. After the revolution he moved back to Finland and founded a workshop i Helsinki, active 1922-1969. He used the same punches he had used in St. Petersburg i.e. H.K. and HK.
I thought that Kaksonen must be mentioned in Postnikova, Ivanon or some other Russian source but, I couldn't find anything about him. Time passed and while looking for something totally different, my eyes caught in Ivanov a name. It was Henreich Johannovich Kaxonen (Iv#1806) ... Kaxonen!? I took a look at the Russian version; Каксонен Хенрик (Kaksonen Henrik) FYI; Henrik is the Swedish equivalent for Heikki. In other words my missing man; Heikki Kaksonen! The text told me that he had a silver workshop on Kazanskaya uliza 33-35 in 1917. In the text was also mentioned another name Andrey Kaxonen ??? In addition, that Heikki Kaksonen had used a punch AK but no picture of it. The name Andrey and the punch AK are picked from the sky. Kaksonen used H.K. and HK. I had, anyway, found my missing master by a coincidence.
What I'm trying to tell is that sometimes the transliteration and as well translation of names can make people almost disappear. What I learned is that it is not advisable to search somebody relying 100% on a correctly spelled name. You should use your imagination of how a name can be misinterpret, misunderstood, misspelled etc.. Then you might find something like I did. Yes, of course you already knew all this. Good, but it is still not so easy to always remember how to search....I thought a reminder would be in place here....!
Moreover, do you remember the famous Fabergé master Gabriel Nykänen? For years his name was spelled Niukkanen (a Finnish name too) and a person with this surname could not be traced anywhere in Finland. It turned out that it was a transliteration error because there is no Y-letter in Cyrillic, so somebody used the Cyrillic letter Ю for the Latin Y and a well known man became "unknown". Later G. Nykänen's place of birth etc. was easily found.
Something to think about in the darkening evening...