When at the glass shop ask them for the window setting tape. Measure the window track, what the glass sets in, so they know which thickness to give you. When I did my '37, I had all the window trim in place with the glass in the up position, heald up with tape. I then oiled up the setting tape with WD-40 and rolled the hand crank up till the track and window were pushed together. The oil helped them slide together plus expands the tape for a tight grip. This was the only way I could figure out how to get them centered the first time. It seemed to work, I ony did it once, maybe I just got lucky! Due to the way they roll up and down, mine bind a little on the way up. It has nothing to due with the glass or seals, just a old design regulator. Joe