Lang,
I've seen that photo a number of times and also noticed the two obvious differences you highlighted.
There is a note in the James oral history about a captured German vehicle and I wondered if the non T could be that same vehicle. I can't explain the different bonnet arrangement on the third vehicle from the left but no doubt there were "exigencies of the service" then, just as there are now. The vehicle is pretty obviously a T.
I don't think the 1916 and 1917 bodies were the same and I'll attach a couple of pics to illustrate. The earlier ones seemed to have a Vickers or Lewis mounted generally rearward, while the 17 Ts used the Lewis mounted forward on a post near the passengers windscreen (LHS). I'm re-creating one of these vehicles and this is one area that I'm still struggling with.
BTW that insignia on the front 17 Ts radiator is the Australian coat of arms with a centred palm tree - I think you can faintly see this same vehicle in the Aleppo line up, you posted. It's towards the right of the line, looking at the cars.
