Chris
While I have read in the past a few books on the Churchill, not sure I could top you. But I do know that some of the pictures are from the Canadian Archive, and I believe have not been published before. What I found real good in this book was the description of the tanks role at Dieppe, with information from actual reports and interview with tankers that were there. And yes there is a section of the gun Carrier, to include the development and some pictures.
In my opinion, this is one of the better books I have read on the Canadian use of the Churchill. And I am glad I bought it.
Kevin