I spotted this whilst visiting Bodiam Castle where artefacts (mainly 14 century) found on or near the premises are on display. On the right is a piece of flint and on the left a flat iron ring on which it was struck thereby producing sparks to light your kindling. So, as with many things that we find, apparent scrap is worth a second look. If you do find such an object and want to enter it in the competition, make sure your bring a piece of flint to demonstrate to the judges that you know what you’re talking about!
Andrew.