I received my copy. I thought I already know everything about the Whippet, but who already knew something of the (second) prototype with a set of tail wheels?
Years ago someone posted a photo of a Gun Carrier on trials (at Oldbury, I think) and in the background was a Whippet with tail wheels. Can't remember who posted it or any other details...
EDIT: It was in the Wheels & Tracks Gun Carrier article, which I have knocking around somewhere.
-- Edited by Roger Todd on Sunday 25th of May 2014 10:18:32 PM