Wayne, if you only knew what you were missing out on putting in lockstrip!  Trust me it was a good decision if the glass shop knows how to do it. (Some won't do the lockstrip at all)  You are correct that it comes out very easy, but it is a trap making you think it will go back in easy. 

Interesting that Scamp is not stocking the old windows now.  I actually looked at a glass shop fabricating mine and they recommended Lexan as well.  I think that was a good decision as well.  Keep us posted on your project.