storm window panel corner

This is a very weird corner. I don't think we will be able to replace it. You might need to take a corner like the 95-054 and cut and retro fit it to your frame. If you want, send us some photos of the frame and the channel were this corner fits into. Please also provide your measurements there. That might help us identify the part that could work for you. However altering a part like the 95-054 may be your only option. I've honestly never seen your corner before.