I know that the big back glass was a premium when these trucks were new and they're desirable now, but how much does it add to the value of a 55-59 truck? I'm looking at a stripped down cab that's for sale and the guy seems to think that it's worth a small fortune because it had a big rear glass. The cab now has no glass, doors, or anything else that could be removed. It's just a shell. I'd appreciate some insight from the experts before I start haggling with him. Thanks.