Unfortunately it is missing the back glass, and I don't know what glass they used in it back then, I am sure it used something already out there, I just don't know what it is, maybe one of you guys have a clue what glass goes in it, I was thinking Barracuda or something of that era.
It doesn't fit very well, I suspect that is because of the way I was storing it, I will let it sit there and settle for a while.
If I am unable to figure out what glass goes in it, I suspect it would be easier to just fill the hole with with fiberglass and then put a smaller window in it that doesn't have the curves on the sides, or something even smaller.