Duplicating, has faded away, the term is no longer heard, the stencils, the ink and the clatter have gone from around here. Roneo was another term.
Gestetner was a Hungarian who began manufacturing in Tottenham, North London and ended up with hugh world wide sales of the duplicating machine. The design was very effective. Mimeograph and Roneo were other contenders. The company merged with others and the NRG Group appears to be the result.
My very last foray with a duplicator happened when a printing supplier failed at short notice and I tried to 'fill the gap', I was inexperienced, it was very tricky but ended up with something like the original.