A quick learner from wisconsin says:
July 16, 2015
Total pin length 1 3/4 inches, Head to end of first shaft length 1/2 inch, remaining shaft length 3/4 inches. Head width 5/16 inch, bottom shaft dia. 1/8 inch, shaft diameter right below head 5/16th inch, I am missing a spring that should be on it. My screen storm trim is 3/4 inch by 5/16 inch. Thanks
Paul from SWISCO responded:
July 17, 2015
Hello, thanks for posting. I think our 70-009 might be what you're looking for. The head diameter is 5/32" thick, which I think you meant instead of 5/16". It is long enough for a 3/4" x 5/16" screen frame. Could this be a solution?