It is eventually hinted that Rudy is an immortal soviet bigshot of some sort, but I've never been enough of a history buff enough to figure out just which one he is supposed to be. I've asked Greg Bear this personally, and he plays coy (he's allowed to do that, your stuff is excellent Greg). Does anyone have any idea who it is supposed to be?
For those unfamiliar with the story, many of the pre-1950s soviets have gained access to technology that makes them indefinitely immortal. They find Joseph Stalin still alive trapped in the cliche science fiction glass container filled with fluid.
I'd ask what those things are called, but that's another question I did end up asking eventually.