Furthermore, the Carden-Loyd Patrol Tank Mk.I used Skinny Tracks, while the Mk.II used Fat Tracks. If you look through pictures of British light tank development in the 30's, virtually every vehicle is using either these Skinny Tracks, or more commonly, the Fat Tracks.
Just an observation I have not seen noted in books before.
If you have a copy of Making Tracks, British Carrier Story by Chamberlain and Ellis (1973) you'll see photos of British Mk VIs with skinny and fat tracks. And it isn't a matter of late or early versions either. I suspect that it was possible to fit the vehicle with skinny tracks for road running etc (saving money) and replace these with fat tracks if the machine was going to be used cross country in combat like conditions. Only a theory but supported by pictures of the VI* (export model for Bolivia, Japan ,Thailand and other countries) with fat tracks (so that Japan would have been sold a fat tracked vehicle)