Or, it could be a serious misstrike. Yes, the diameter is crucial, as the design looks as though it's been struck on a larger flan, but this would only be clear once we knew how it compares to a kosher 5p of the day. The overall appearance is of a coin that's been machined in some way. It does look weird. Hi, it is 25mm in diameter, just got hold of 1970 5 new pence to compare it. it is only 22mm in diameter so it could be the crushed idea. Thank you for your input. Ray.