I've been looking at the drawings of Cromptons landships recently available through the link posted in forum. Now I understand that the Crompton patents specify the use of Bullock track units but those on the drawings would appear to be closer to Holt. Anybody got any ideas?
They're Bullock tracks in the drawings. Bullock and Holt tracks looked very similar (even in patent drawings), but one easy way of telling them apart is that Bullock sprocket and idler wheels had curved spokes; those on Holts were straight. Compare the drawings with the drawings of Lincoln Machine No 1 which carried Bullock tracks (and of which there are photos here and there). Attached is a photo of a Bullock Creeping Grip tractor (of the type Crompton tested).
Those drawings are based on the ones Dick Harley did for Tankette many moons ago, and he really knows his stuff.