Mine was the same way. I took a punch(not a center punch), and hit right in the middle on both sides. Does that make sense?

Just in case it didn't. I used a punch with a flat face. Maybe twice as big as the head of a pin. I placed in the middle of the barrel over the dovetail, but still back a bit from the edge of the dovetail. I didn't want to bend over the edge. A couple of hits on each side gave a perfect fit.