I just picked up an Iver Johnson single shot, black powder 12ga. and have some questions for the experts. 1. Are these safe to fire with current 12ga. shells? If not where can I find shells for it? Do I have to handload? If so, where can I find the stuff to do so? 2. How do you tell the age of the gun? 3. I picked it up for $69. Is that a fair price? I am just curious as to market value. It is worth it to me simply because I like the cool brass buttplate with the word "Champion" written in scriptive lettering. Any info would be appreciated. Thanks.