I don't have a PRO ref. for that document, however it is held at Bovington and their reference would appear to be "BTM Tank Supply/8"
The Document title is D.R.A.C. Library Serial 001066, Progress Report No.2 and the page in question comes from an Appendix to Chapter III (I don't have anything other than this single page).
P.S. I've corrected the mistake on the Valentine MkX figures.