It is also well to note that "Patent #488,366 Dec 20, 1892" (US) was not for the bls, but the lock mechanism (not bolts). His US patent #246,195 Aug 23, 1881 covered his original style of "Mono-Blocked" (To my knowledge he never used that term) bbl joining. This was the style where the tubes were inserted from the breechs of the block & have a stepped appearance. These are often found on guns marked Original Diana. Also to my knowledge he did not have a patent which covered the method of joining shown on the bbls marked Modified Diana. On this method the tubes stepped & were inserted into the front of the block. On one I have the tubes only go about halfway through the block with a joint in mid-chamber. I am not positive but highly suspect they are threaded into the block.
Also not positive, but highly suspect Berretta "Coined the Term" MonoBlock.
