I bought some 16 bore cartridges in the sealed bid auction at Holt's, and they appear to be, shall we say, vintage. In the red William Evans box are paper cased Holland & Holland cartridges with Eley Kynoch headstamps called "the Dominion" and "Super Sixteen". Then there are several blue boxes of plastic cased Eley Grand Prix Waterproof cartridges. The box refers to Imperial Metal Industries (Kynoch) Limited. Any idea how old these are?