The Breakdown Car shows the same differences in bonnet shape as the Motor Car does (understandably).
Now it strikes me that they show a parallel difference in hook mounting orientation, anyway, mine do.
The flat bonnet/straight lower windows line model (the grey one in the middle) shows a right side crimped hook mounting, whereas the higher bonnet/angled lower window line example(s) show(s) a left side crimped hook mounting.
Is this a 'rule' or do other examples deny this?
Furthermore, it strikes me once more that the crane is a rather intricate, vulnerable piece of diecast (with the rest of the inserted base) and not the same thicker, sturdy tinplate that the later Commer Breakdown Lorry uses.