55-303 anderson casement window stop

I have a Anderson casement window missing stops I found a stop for a at swisco that looks and measures almost to an exact replacement except the top of old stop lays flat on glass and the top of new stop has a little return to it.my question is did Anderson make a change o this stop or has time flattened out the top of stop.

Dave,

Thank you for a response to my inquiry I have attached a picture of the stop in question along with a picture of the inside of window the only markings I could find was on the crank handle cover has eagle stamped on it and I understand that Anderson has bought out eagle. On the stop 55-303 all the dimension are the same the only thing that is different is on the top of the 55-303 tip has a bend to it were as the stop I have the tip goes straight up. My thought is that because of the heat here in Las Vegas that it has taken the tip of that stop and actually flatten it out which would explain why they have fallen off of these windows.

What is your thought on this keeping in mind that all dimension are the same . I would appreciate a quick response so I may place an order and get back to the contractor and let him know.