RX-75-1 through 3?

[Rawinder]

Has there ever been any kind of word on, or look at, the earlier versions of the Guntank? There's an RX-78-1 and an RX-77-1 but I've never heard of an RX-75-1, -2, or 3.

[Rawinder]

heh, well I suppose no one else has either!

[Strike Zero]

As near as I can tell, the -4 in RX-78-4 was used merely to indicate that the Guntank used aboard the White Base was the 4th Guntank of the RX-75 line, rather than some sort of 4th iteration. Nowadays, RX-75-4 seems to be something of an outdated number when it comes to official sources, in that most modern source materials tend not to use the -4 suffix at all, simply referring to the original Guntank as RX-75.

Now, when it comes to the predecessor of the Guntank, one did exist in the form of a limited-production next-generation battle tank called the RTX-44. No official illustrations of this prototype exist, but we do have a clue as to what it might have looked like in the form of MS IGLOO's RTX-440 Guntank Ground Assault Type, which was more directly derived from the RTX-44 than the RX-75 was.

[Zerosystem]

Here's a scan, probably from the master grade Guntank booklet.

http://i.imgur.com/URs2bGj.jpg

Prior to the Guntank we see in the show, there would be the original RTX-44 and according to that picture, a RX-75 prototype that I can't recall correctly if it had a core block system or not.

[AmuroNT1]

Have a larger and cleaner version of that scan: http://dalong.net/review/mg/m123/p/m123_m0003.JPG

From what I can see, the Guntank Test Unit 1 seems to be based off one of Okawara's unused design sketches (sadly I don't have the artbook handy to verify).