(1.) The circles around the numerals of value are double lined.
(2.) Neither of the 5's touch the circle.
(3.) Exp:do. Ref: Varro Tyler, "Focus on Forgeries"
1.) Both circles are almost solid, rather than double lined.
2.) One or both 5's touch the circle. In this case both of them do.
Exp:do. Ref: Varro Tyler.