Hi Chuck & Lynn,
For the most part '66-'68 have curved Corning glass windows, except the
front and back windows. The glass there is flat, but still needs to be
tempered glass. Any number of glass companies will make flat tempered glass
to size, but few are willing to make curved tempered glass to match the OEM
specifications. It is possible that some very early production '66
Airstreams were made with '65 design windows. Prior to '66 window glass was
flat, and was just the same type of glass you can get from any hardware
store. After '65 Airstream windows fit flush to the contour of the body, and
are curved, but from '69 to the present the windows also had radius corners
and the glass is enclosed all around with a frame. '66 through '68 are
frameless, rectangular, and curved. Made originally by Corning, the glass is
thin, flexible (to a point) but strong - a real space age, let's go to the
Moon type of material. Many think it is a cool looking window. When it's
open, it is visually unobtrusive, almost like it is not there, but as cool
as that may seem it is also a drawback - it is easy to walk into (ouch!) -
and since it hasn't been made in a long time it is hard to find glass
replacement. Up to now the only choice has been to replace with plastic or
salvaged pieces.
Forrest