Well, I had two Argus C3's at one time - both are gone. I had two Mamiya TLR bodies - not identical but close enough - one remains. I have a couple of Bronica ETRS bodies, but one is set up with AE prism and grip, while the other just has the WLF. I have a couple of Nikon RFs, but one is an S and the other an S2. I have two Leica Barnacks, but one is being modified to at least look very different from the other. Seems like I have an aversion to out-and-out duplication.