Nice looking track rig.
In reading the above posts, did I miss how the steering works?
A suggestion for you if you redo the tracks. When you install the grouser bolts, reverse them next time. The way they are now, the heads will get rounded off on rocks and hard ground. With the head rounded off you won't be able to get a wrench or socket on them. If that happens your only option will be to cut them off with a torch possibly burning the track rubber.
When you turn them around with the bolt threads sticking out, yes the threads will be damaged, but you'll still be able to get a 6-point socket on both the bolt head and nut. The nuts will be hard to remove, but a good impact wrench will take care of it.
Bill