I just brought out a book with New Island, entitled ‘D’You Remember Yer Man?’ I’m attaching two pictures from the launch – one of the actual key that Bang Bang used (top) to shoot thousands of Dubliners, and one of myself (left) with Ruan van Vliet (who illustrated the book) & Aidan Walsh (centre), aka The Master of the Universe (one of only three living people who feature in the book). The book is available from all good bookshops in Ireland, and also available online from New Island Books, Amazon, The Book Depository, etc.
These vintage devices are sometimes confused with early spy gadgetry but the truth is much stranger. Sez David Galbraith of Oobject:
Jailers’ keys were apparently filled with gun powder to create a primitive gun that could be detonated if there was any trouble when opening a cell door. We found several original versions that back up this claim, dating from the 17th century and of various complexity.