I run into these windows everywhere in the mid Atlantic area. Cannot find parts anywhere. It is basically the same corner as you part number 95-254 but of course it is nylon and not metal and the dimensions are reversed from your part. Meaning it is 1/4" where yours is 7/32". And 7/32" where your is 1/4". I hope you have a solution. I am having to turn away a lot of customers because of this. These are extruded aluminum frames that are pinned to hold the corners.