Ours leaked, went to a automotive glass shop. The drove a pick-up truck sideways in front of it and then put a step ladder in the back of the truck. The owner of the glass shop used something in a tube in a caulking gun. Said it would seal the window perfectly, but not harden up. Took him 30 minutes, it was cheap, and haven't had a leak in three years so far.
Go by a couple of glass shops, you might even find one that works on restorations, take a couple pictures of your windshield on your phone and talk to them. It's a lot easier than doing it yourself and for very little money.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.