I have an early Mk3, serial no. 31:
This has the 'double pull' i.e. two stage trigger of Diana design and I also have a later Mk3 with the second type trigger with the really curly trigger blade, but I don't have a picture of that one to hand.
The double pull trigger to me is an excellent trigger, well ahead of its time and better than a lot of current triggers on springers. I have to say I really like it.
The second type trigger is not as refined but is still a respectable trigger.
The later triggers just don't seem to be as good.