Security screen door hardware

I recommend looking at our 40-119 to start. Out this may be a good match for your old security handle set, but without seeing the original I won't be able to confirm for sure.

I can't see much of your original hardware from these photos, just the door and the face of the mortise. Your next step now should be to carefully look over the photos and dimensions we show on the 40-119 store page. If they differ in any way, you will need to let me know how and provide me with pictures of the specific differences.