I am presently restoring a 1952-60Special and I bought new windshield and rear window rubber seals from Steele's.
Now, trying to fit the original panes and the new seals into place, I found that it is impossible. Naive as I was, I first tried with the sealing compound in place and ended up in mess after an hour of trying to fit the unit in place.
After cleaning up I tried the same with just dishwasher detergent to aid in slipping the unit in. No dice!
Tried the same in the rear - same story. The rubber front and aft is too thick between the bottom of the glass channel and the bottom of the rubber where it sits in the body recess.
In my opinion the only way is to shorten the panes by about 1/8", maybe even a little more.
If anyone has had a similar experience, I'd gladly know about it. I assure you that I have made the installation according to the book, with strings and all, but I am sure the replacement rubbers are just too thick.
Also the bottom corners of the windshield seal, when pressed in where they belong right and left, shove the half round parts of the lower rubber (where the wiper transmission and the washer tube go through) too much to the middle so that those half round rubber parts cannot enter their corresponding cutouts in the body. Those vulcanized cornes too, have to be worked thinner by shaving material off the outer rim to make them settle deeper into the body corners right and left and so let the half round parts settle in their recesses.
Any opinion is most welcome!!