A friend recently inherited a Colt Viper. He is interested in selling it, but needs to determine the value first. GunBroker has a couple and they are going for a considerable amount of money. However, those include the original box and paperwork. This one is just the gun and apparent aftermarket grips. No box or paperwork. I am not sure how much that would affect the value. This gun seems to be pretty rare. Your help is much appreciated!