We all have things to learn from these discussions. I recall (a little foggy now though) a dispute a number of years ago between Bill Mook and other Krag collectors, Scott Duff for one at the Baltimore show about blueing of early bayonet blades. There it is in the 1895 report:
"(4) The blueing of parts of the bayonet discontinued, as the heat of the niter bath was found to injure the temper of the blade"
Good solid information many thanks