Showerthought: The worst tempered glass job I ever had was in a 1920s apartment building downtown.
We had to replace a huge transom window last month, and the old frame was so out of square. The glass guy before me just forced a standard pane in there years ago, and it finally gave out. What's your go-to method for measuring in those old, warped openings?
My old boss taught me to take three width and height measurements, top middle bottom. You use the smallest number from each set for the final glass size. That extra quarter inch of clearance saves a lot of headaches on those crooked frames.