Thanks for clarifying Per - for some reason I thought the bracket on the RHS was a solid one, not one with an open top, and the LHS one just a peg on an angle perhaps for the old track cable - so I couldn't quite see how that kind of saw could be mounted on them. Their alignment still looks a little bit out of whack with straight, even on that slight angle - but so far that is best answer I think we'll see, so I will play around and add one tonight
It does seem odd not to protect the toothed edge from damage (or the crew from the teeth) in a cradle of some kind though (a'la the Russian T-34s etc.)?
While the ubiquitous axe and tomahawk are on everything, I'm surprised that larger saws weren't a bit more common on their vehicles? As you say they would be handy for camo branches, clearing fallen trees or limbs or even a path through wooded terrain if they got boxed in. But perhaps more importantly for vehicles of this weight - cutting large simple unditching logs to free them from boggy ground would be hard work with a medium size axe. Maybe they normally just waited for the engineers to arrive to do that sort of thing?
Anyway thanks again for your patience and help in I'd say pretty much solving this small riddle. I'll post some shots of my version of it a bit later on.