This is really excellent work. My congratulations. I am carrying out my own research into the British tank factories and it would be great to find this much information!
I have spotted one small error. In photo 63, the 'Mark IV' is actually the Mark II Experimental Machine A fitted with Crochat-Collardeau petro-electric transmission. This is mentioned on pages 107 and 133 of Sir Albert Stern's "Tanks 1914-1918: The Log-Book of a Pioneer". Just last week I found records that show that after the machine was no longer needed it was given to the French Government.
It's only the superimposed text on image #63 which is in error. The caption says "180807 - De Souce britannique bien informée, il s'agit d'un Mark II expérimental. Ce char, testé en Grande Bretagne avec une transmission pétroléo-électrique Crochat-Collardeau a finalement été donné à la société FAMH. "
Google renders this as "From well-informed British source, there is a Mark II trial. This tank, tested in Britain, Petrol-electric transmission Crochat-Collardeau was finally given the FAMH society.
This Mark II was the only one fitted with the Crochat-Collardeau transmission. It missed the Oldbury tests and was allowed to be retained by the French Government. What happened to it I don't know - anyone seen it recently please let me know...
Thanks for the great contribution, especially the photo of Mark II (Crochat-Collardeau petro-electric transmission).
The 800th St. Chamond is effectively the last manufactured. However, it has only one tower, so all subsequent changes "only" modifications of the basic version (except the cannon)?
For more information about "Oldbury transmission trials" (March 3, 1917) there are in the Landships - British tanks in the First World War (David Fletcher), page 22, 23, 40.