One theory of mine considering all that we have discovered about this type of swords is that theywere originally longer for cadet training in Toyama .reasons being the ubu ha,the longer nakago, overweight blades for the length,thicker kissaki ,conform to takayama 2nd design specs. Possible? As compared to the Bujin-to 1939 Naval Nlf specs ,aka Rikusen-to. One other possibility is they were intended to be a Naval Rinji Seishiki as their nakago length was 242mm w/ 2 mekugi ana.