47-55.1 1954 Window Regulator / Glass Adhesion

[Darthintel]

On my 1954 Chev 3100 the drivers side window regulator is not attached to the window. The metal strip that attaches to the glass was in a box when I bought the truck. I can move the glass up and down with some effort and due to resistance it doesn't fall down.

Questions:
1. How is the glass adhered to the metal channel? I can see some type of material in the metal regulator where the glass goes in, almost looks like leather. If glue - What type of glue would hold the glass in the metal channel? Or do I need to wedge the glass into a piece of rubber for a tight fit?
2. I assume the metal channel can be placed back on the regulator then attached to the Glass without removing the regulator from the door.

I will also need to free up the glass after it's attached to the regulator.
Weather is warming up and I'd like to drive with the window down.