Anyone have any info on these two different designs of 31 spiral springs?

I think there were at least 3 different models. One of the differences is the lever. The third model (not pictured) had a wire lever.

The early spiral springs were constructed with small springs inside the levers following the Triumph model Those springs have a short life and are difficult to change, Later traps were made with the springs outside the levers like modern coil springs. I have seen the small springs only on #1, 1 1/2, and 2 size traps and have not seen them on the #3 or #4 size traps.