I don't think it was double struck. The doubling is most likely the result of the stamping on the back. The coin was probably placed on a block of wood or softer metal and then struck, the surface was indented by the obverse of the coin becoming sort of a die itself. As the letters were struck the coin moved around causing the double image on the obverse. It is also possible multiple coins were struck with one stamp and the coin picked up the doubling from the earlier stampings.