U should check on the anime profiles. They have information on all the gundam series (I think) and it tells u who made it.
Anyway, what were the names of the first three and the last one? Or were u just referring to the ones RedXIII mentioned?
Well in the first three the Gundams don't change, only the pilots do. (or how ever you spell pilots) In the last on though everything changes. The Gundams like RedXlll said turned into "cute" Robot-like kids.(In a manner of speaking) They used to be 50 feet tall now reduced to under 4 feet.
Well the Gundams have names and are all unique. In the first three the Gundams The main Gundam is piloted by the King of Spades,(Don't ask my why) and that doen't change. The basic drone Gundam has a gun and thats all. Other than that the Gundams don't change