How Did The V&A Know They Were Nipits?

I read in the paper this morning about the discovery, by V&A curators, of two small throat lozenges in the pocket of the Aquascutum suit that Margaret Thatcher wore to the 1987 Conservative Party conference.

I seldom visit the pharmacy in Waitrose but had cause to today. A big pile of the little black, white and gold Nipits tins, which I have never heard of before, were piled up on the counter. I asked the assistant if they had been put there because the lozenges are in the news. She hadn't heard the news and said that they are always there. I bought a tin for MrQ as he croons on his gigs. They're meant to 'clarify the voice and clear the throat.' We were surprised that they're unwrapped and very reminiscent of mouse or rat droppings in size and appearance. :)