This plate, or is it safe to call it a charger?, took my eye at an auction tonight and I'd love to know more about it, but don't really know where to start looking. It measures about 16.5" in diameter (42.5 cm) with uneven raised edges, a smooth surface and depressed? impressed? underside with a slight texture around the underside edge. If I had to guess I'd say Scandinavian and I'm sure I've seen something like this before, but smaller, but can't remember where. Any ideas gratefully received, Thanks, Iain.