I used the stacked plywwod method on my S&G. I did not use any glass but instead just brushed on some epoxy for abrasion resistance and sealing of the wood. The plywood is strong enough on its own to not need the added structural strength of the glass. The coating of expoxy can be sanded to a nice smooth finish.

Just my thoughts. And I recall reading this somewhere else as well but can't recall on what website.

http://justyakkin2.blogspot.com/2011/03/some-days-are-dust-and-some-days-are.html

Sean