Further looking after all the pics were downloaded (I'm on dial-up) showed these bbls to have a later construction method than that covered by the 1881 patent. These bbls were possibly threaded into the block from the front & go only part way through the mono-block, at least that is the way one I have is made. It however does not have the Bayard name only Pieper & is marked "Modified Diana" on the bbls.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra