Just to let everyone know if they didn't already, there is a SBL Griswold for sale on Goodwill's site that measures 19"x14.5"x3". Goodwill is bad for descriptions and pictures but it's a monster pan. Here's the link:
http://www.shopgoodwill.com/viewitem.asp?itemid=25880144
http://www.shopgoodwill.com/viewitem.asp?itemid=25880144