Based on the dimensions shown, I believe that I am looking for the 5/8" top sash guide (18-009). My part has only one screw hole (the 3/16") and has a part number H-719. Can you confirm that I have the right Top Sash Guide?
Paul from SWISCO responded:
February 9, 2017
That number you gave us, H-719, is more often associated with our 18-177. However this is far different from the 18-009. I think it would be best if you show us a few pictures of your top sash guide. Please also confirm your exact measurements.
A quick learner from Mesa says:
February 21, 2017
You are correct. It is the 18-177. I ordered several and they were a perfect fit. Thanks for your help.