MPC has re-released their old (1970s) Titan III and Vostok kits, originally as either flying rockets or static display models. They were kind of basic, but not bad actually, the Vostok was in 1/100 scale, a nice middle size build, and could be a Sputnik 1 or Vostok 1 launcher. The Titan III, though claiming to be 1/100 scale, was actually closer to 1/120, with the complication that the Titan core was a bit over-size in diameter where it should be actually just the tiniest fraction smaller in diameter than the solid strap-ons.
The re-releases don't have the flying option, but are other wise pretty much the same as the original.
Since I can't resist the chance to do something other than out of the box, I'm building the Vostok as a Soyuz launcher, and more relevant to this site, the Titan III in its original intended role as the launcher for the X-20 Dyna-Soar. So all I have to do is scratch build the X-20 and adapter. So here is where things pretty much stand. The X-20 is built-up out of bass wood, the elements soaked in thin CA glue to have a hard, easier to finish surface, as is the adapter. I'll be casting the new parts, and can do copies if anyone is interested.