Posted for "Marshall Michaelian" <mmichaelian@comcast.net>:

 Judy's Aircraft Windshield (562-430-8108) made my molds in the exact same
 location. I formed a box to go back over the leading edge to 2" beyond the
 expected lens.  I used dental die impression stone (pinkish stuff) to make
 the mold.
 
 Call her and she'll walk you through what to do.
 
 M Michaelian (SQL, LIV-PT)