Revell has released some old Star Wars kits

[chromedog]

Yes, and it can be used to make different variants as well... There was one with the wheels in the concept art of original SW, right? And a hover version would be nice as well... Should I start buying Imperial Assault minis?!? 

There was a TRACKED tank idea in the original concept art, yes.
(and an aquatic one that got used in one of the old rpg scenarios).
I don't recall a wheeled one, but I think it was mostly Joe Johnston's stuff in that empire sketchbook that I have. 

[OSHIROmodels]

There was a wheeled concept but it became 'canon' and is called the Juggernaught. A version of it made an appearance in the prequels.

cheers

James

[huesped]

Yes, Jim; the Juggernaut first appearance was on The Imperial sourcebook, published by WEG.

[beefcake]

Imagine the price then for a 28mm, 1:52(or whatever it is) scale! So much else I could do with that cash.