Very neat projectiles. Would love to add the 12 pounder size to my collection. I remember back in the 70's I was hunting a hill across from a fort on the Mississippi River and I found the canister version of one of these (flat top rather than the cup) and a few large lead balls around it. Had no idea what it was. There wasn't much trash there and it looked old so I hoped it was something Civil War related. When I found out what it was I high five'd myself.
Some month later not too far from that in the bottom of a trench I dug a dutch oven upside down. Under that was a hotshot base and a 6-lber ball. one of my favorite holes ever. Again I had to high five myself but was glad to.
I'd really get excited to find the 12-lber size.
When Dr. Pawl started putting his James collection together I was building my first house. I sold the few James I had to him though Jack Melton which included a James for the rifled 12-lber. One of the many shells I sold over the years that I regret selling.