The Shimano Lark is a Skylark with the cable clamp bolt mounted on a sprung ‘cable saver’ arm. I have always liked this feature as it gives a pleasant supple feel to the gear change.
I think this example is the second version. The difference from the first style is that this Lark does not have the screw pulley cage stop.
This example has clearly put in a good few miles - but is still perfectly usable with tight rivets and lively springs.