[ercoupe-tech] Replacing glass

[ebenguiat1]

Hi Everyone,
My rear windows on my G"model are deep scratched,
 one has a fine line crack which has been stop drilled.
I want to replace them both from Univairs. 
Don't know if it's Lexon or Plexiglass. 
What is the best of the two products.
 Your valued opinions are all important to me.
Thank you,
Prof. Ed