The edge is very similar to that of an Irish Pound coin (Punt)

although unfortunately the irish pound coins weren't issued until 1990 so it couldn't have been a mix-up (There's 2.5mm difference in sizes of the two coins too)

although unfortunately the irish pound coins weren't issued until 1990 so it couldn't have been a mix-up (There's 2.5mm difference in sizes of the two coins too)























