Yes, thanks for the picture, Walt. Now I've seen one!
Do you know if they had 3" chambers from the start or are there some with 2 1/2" and later ones with 3"?
LOTS of mythology about these "cast iron receivers" out there on the Web....I always wonder how much of that starts as "leverage" to get doubles cheap. I've heard "dealers" tell owners of old doubles the equivalent of "you better sell it to me for the parts, 'cause it will sure blow up in your face if you try to shoot it!" "When the emotion is right, the sense doesn't much matter!"
(I actually heard that first applied to the Stock Market by an experienced broker....)