Searching for spring loaded fingertip latch

We need replacement parts for an aluminum "L" shaped pull/latch for sliding (up and down) storm/screen windows. I was unable to find any part no.s on the window or parts. I have included the front of the working replacement we had bought in the past:it has the fingertip pull. The back views have the spring.
Do you know what these pull/latches are called, and do you have them or a similar replacement for sale. If not, who might?

Thank You,
N. MacDonald