Oil Head, one thing you can do is go to some shows and ask questions. There are a few details that will eliminate about 90% of your concern. Some dealer/collector who has been collecting for 20+ year; and is reputable can explain things in a few minutes and most would be very happy to share their knowledge. AND stay away from ebay! You WILL get burned! I've been collecting 35 years and really haven't looked at ebay in 10 years. That is a dumping ground and scammers! Just my advice and opinion.