British army trucks of the 30s: identification

[Konstantin Chernov]

1. British half-track, 19 february 1935 . The drive sprocket (or idler sprocket?) is very similar to the one fitted to the Burford half-track. But the car itself doesn't seem to resemble a Burford.
2,3. Half-track Burford 30 cwt 1926.
4. Half-track Burford with a caterpillar drive of a different design.
How were the models of all the above mentioned machines designated ?