Legs are 1 1/2"L x 1/4"W x 1/5" H.
I would need four plastic parts. I was told they were manufactured by Simonton. Is this correct? Do you know where I could find replacement parts.


Look at the 95-187 corner key. It has a 1" X 1" square like you have. It is for screen frames that are 5/16" thick. It is not exactly like your corner key, but see if you can adapt it to your screen frame.