@Victorian - nice route!
I think it should be feaseble to do it solo. IMHO getting a slot in Pulkovo is going to be the most troublesome/expensive task.
There is no avgas at Pulkovo. Local pilots mentioned that they might be able to organize a delivery should we need it, but we were fine. One of our crews flew a C172N and brought some extra Avgas from Helsinki in a jerry can.
Meters are not a problem - Russian ATC provides you instructions in feet and they speak English (though with the heavy accent). Our group of 7 aircraft flew in Russia with Russian crew in just one airplane (i am a Russian
According to Russian AIP, you must have Russian VFR charts on board though.
I suggest you to contact Russian AOPA; they did a tremendous job helping us make it happen. If you PM me with your email I'll send you their contact details.
Mike
--