Is this really a glass tank set inside a plywood box? I see that it has a glass front, but the rest of the tank is also glass, isn't it? (Maybe this was alll explained and I went through the explanations too fast).
The inside will be coated with epoxy and fiberglass. This is actually a very common style of tank. I can get you links to one tank that a Mod at ReefCentral made that I believe is around 400 gallons and another tank that a member made for sharks that is almost 1300 gallons.