Back in the late 60's or early 70's I did build a Tamiya Mokei model of a Pzkw III Aust. J that was a motorized kit in some strange scale such as 1/21 if I recall correctly. It has treads that are essentially big textured rubber bands, which are probably rather brittle now and have likely taken a rigid set around the drive wheels. The details of this discontinued model are not up to Tamiya's modern standards, but it was pretty good, and probably the best available at the time. I somehow managed to R/C this one with the huge three function servos then in vogue from the only proportional systems available at that time .... Kraft. Four channels allowed for forward/reverse steering, turret rotation and gun elevation, and it was absolutely all that would fit into the hull to accomplish that.
The current era of RTR in 1/16 scale were a true revelation to me when I first came upon them. Thus it was a must have, especially at the price!