This was actually the first tank model I ever built myself. There were two versions of the Aurora MBT-70 produced; the original "smooth" kit and a retooled "textured" kit.
That's the original issue, the second retooled issue came in the small white box. The retooled "textured" kit includes a gritty non-slip texture to the upper hull and turret surfaces. They also added a coiled up cable to the upper surface and some additional suspension detail to the hull sides in between the road wheel arm gaps.
There's also third boxing of this kit. A white cardboard box version that was part of the Young Model Builder's Club and was mailed to members. It included the later "textured" kit but had a sticker with the artwork of the original square box applied to the box. It's the more rare of the three boxings.
I have several of these kits in the three different boxings (only one in the cardboard mail box though).
J-Hulk (Brian Keaney) built an accurized version of the kit about 5 years ago, I then sent him a spare kit so he could do one OOB. I don't remember which one I sent though.
Brian Keany's MBT-70In this shot, you can see some of my Aurora kits and a couple of the Bandai ones as well.
