I have also learned from my email to Russia that the Porai Koshits have 2 lines, 1 from St. Petersburg, Russia and the other is from Kiev, Ukraine. He did give me a name of a man doing research in Kiev. I have replied asking how to get ahold of this man, I cannot find anything on the internet to make contact. We do know that William did at one point live in Lugansk, which is now part of the Ukraine. Lugansk seems to be about 600+ km from Kiev. My assumption would be our link would be through the Kiev line. Hopefully, I will be able to make contact with this other Porai-Koshits and be able to continue with this search.
I fear that this is going to be a hard line to research. The language barrier alone is going to make this difficult. I did find the Russian Nobilty Association which will assist for $100 to do basic research in Russia. Then $25 per hour if we would like further research.