I've just found reference to this in the IWM catalogue. Its full title is "Infighter the history of the 9 Battalion, Tank Corps 1916 - 1919". It seems to have been published by Valentine, NSW in 2004.
I've never heard of it. Has anyone seen it and is it any good?
This short blurb on Abebooks might help you make up your mind:
"197pp., b/w pls., maps, appends., index, Based principally on two documents held in the Library of the Tank Museum Bovington ; the Unit's War Diary & 'the War History of the 9th Battalion, Tank Corps'. Includes Casualty list."
Thanks PDA. Since posting David Fletcher tells me they have a copy of the manuscript. Unfortunately it seems to be based on the two sources you list with little if any other research, so you might as well just look at the War Diary and the War History.