Very peculiar! I gave you a suggestion about an hour ago, but it appears to have got lost in cyber space.
Here we go again! I wondered if 1852 might be something to do with Otis's invention of the lift in 1852. Can't quite work out what the 'M' could be though.......
Thank you both for this. I did not get the normal alert in my email box that someone had answered my query so i apologise for the delay in replying.
I had googled "inventions" (as I have 'introduced' and all manner of 'I' words) and noted that Otis had invented the lift as well as the escalator and reached the same guess, but his first name was Eleisha so why not E O I the L?
Oh, it's driving me crazy!