I wish I had a set of 2006 loose coins for comparison. All I've got is sealed 2006 sets. I think it was struck in a £2 collar because it's the right size. The edge is irregular, kind of varying thicknesses and some of the milling is missing. So how come there are elements of the £2 design on the IKB side? It has chains in the top left of the reverse, like a proper £2? The rest of the outer part are pure 50p, apart from the shape and edge milling. I'd love to send it to the mint to see if they could explain exactly what went wrong....But I don't want it dissapearing for months!