I had read that though it was invented earlier, it wasn't really used commercially until after WW1 so I tend to err on the side of its-not-as-old so I don't get disappointed. It also has an earlier locking clasp that started I think in 1890s(?) through early 1900s so I go with 1900-ish when people ask lol.
I remember every piece I had to leave behind back in the early 80's when we were poor newly weds. I try to forget but can't-as long as it doesn't still hurt too much it's OK. But God- the sheer amount of 'sleepers' around back than was something !