I was amazed when I first saw this tonight. I thought the white spaceship at the top was a basic Nuclear Ferry! Alas, its not but I'm sure it would make a good basis for one! Its certainly the closest to another Ferry shape I've seen in model or toy form besides the Century 21 original [pictured below] and the SpaceX miniature.
According to Dr. YoKai of Beyond the Sprues it would appear that it is one of the following parts, although I don't know which one: "the Airfix Vostok, Monogram US-USSR Missile set,Glencoe Obs.satellite, and fishing bobbers".
Has anyone got this white spacecraft kit?
You can follow Dr.YoKai's progress with this model project on Beyond the Sprues.