Chuck,
Be sure to remove all the Digest if you 'reply' back to it - you'll see
what I mean when you get tomorrows Digest...
As for replacement panes, the standard is single strength (3/32")
glass, used from the 1930's to 1980's in the all except the 1966-1968
side windows. In 35 years of trailer travel, we've never lost a window
to breakage, and the clarity over time still can't be matched by
acrylic/lexan replacements. The glass on the '56 Flying Cloud, once
cleaned up, is still crystal clear.
Best of luck,
RJ