... I would say that the string needs to start where you first insert the "window frame" into the rubber.
In the early 1960 models, the windshield has to go into the TOP first because of the overhead eyebrow over the windshield.
wrong according to the factory .... the eyebrow [same as 55-59 trucks] has no effect, the glass is placed against the opening all the way around before the string work starts, and the rubber is pulled on bottom first
Bill