I have finished it.
It will turn the wheels if you hold it in the air, but can hardly move itself across the floor.

You will have noticed that I relocated the Scout and shortened the frame.
The shortening would have helped the turning radius if it could move.

The reason it couldn't move it because the 8466 instructions did not make the front end strong enough to withstand the torque that this thing needs in order to move.
The 12-tooth bevel gears slipped causing the thing not to move.

NOTE:  The 1st - 3rd pics are the for the first info
The 4th - 8th are for the second info