Check out Yota Yard.com. They should have one somewhere around there and they can ship it.
I wish I was closer, I have a spare non defrost rear window.
I'll look into the shipping cost of a wood box the size of that window for you if you can get me your ZIP Code
Silly question but do you just need the glass or a whole new tailgate with glass?
I haven't seen my glass in years since I got my soft top. It's still in there somewhere.