Pipe dope is a semi thick liquid thread sealer applied with a brush. Plumbers putty is white or gray and looks like window glazing putty and is normally used to set/seal sink drains. I have replaced a number of both front and rear windows rubber seals on W123 coupes and sedans and the installer charges $95 per window and this is Southern California in the last year.

I do know that the rear window needs to be removed when replacing the headliner.