Picked up this today. It's a huge copper, about 27.1 grams. I didn't buy it as an error, but looking at the "ÖR" on the reverse, there seems to be some sort of doubling. I think there may be doubling on the other features as well, but that's where it's clearest. I don't know anything much about error coins, so I would welcome any advice as to what's going on here. Double strike?