The only thing I was going to make sure and allow was any of the old Czarist ships that were taken over by the Reds were to be allowed.
That way you could let the builders that like to do pre WW1 and newer ships get involved with the campaign.
Other then that I would suggest a time line of 1920 to the break up of the Soviet Union. That is a big era to cover and a lot of ships to think about building.
Cheers,
Bruce

























