I can't answer the hyrdroboost question, I just don't know.
The serial number plate should be in the driver's side door opening on the cowl. The model portion of that number will either be 15 something or 25 something. 15 will be 3/4-ton while 25 will be 1-ton.
The 3/4-ton dually I saw had 150 in the grill and I commented it had the wrong model number for a 1-ton and a guy behind me proceeded to correct me. Turned out he was right.
Price is hard to talk about without looking at the truck in person. You can look it up in Old Car Price Guide to get a ball park. Those numbers always seem high to me. The real question is are you willing to pay what they want or can you read agreement on price.
Right now prices are a little depressed from where they were a few years ago. There are a lot of guys out there who spent big bucks on restoring trucks in the last ten years who would like to recover their investment and are unlikely to manage that.
A truck that was restored 20 years ago is likely priced more realistically in today's market.
