[roadracer]

You don't need to convert at all if you"ll just glue your glass back in using a modern adhesive. 3M makes a Urethane adhesive specifically for windshield installation that is available from most good automobile paint and body supply stores. It's black and comes in a tube for use with a caulking gun.

I re-glued the windows in my 69' this way many years ago after the PO used silicone rubber (ugh)...). They're still there,, nice and tight!