windshield replacement thoughts

70 Duster. I have a bad leak up front on the drivers side I am almost sure is from the windshield seal. I've replaced the wiper seals to no avail. I have some work to do to the car over a short period of time and I would like to remove the glass, replace the dash pad, and have the glass replaced as quickly as possible so I can get on to other things. Would it make sense at all to even consider having the glass replaced by one of the available 'come to your house and fix your windshield' companies? I don't have a lot of time to try this myself and screw it up. Or do they just not stock this sort of thing and it is going to cost me so much I will blow a sphincter?