Rare Spiderman

I have in my collection a rare Spiderman. This was purchased about 3 years ago from a collector in Amcorp Mall, back when my son was in his Spiderman phase. 

What makes this rare, is that this Spiderman has 2 right palm and fingers on both hands.It is clearly visible from the picture below. I do not know how this got into the market by the makers but I'm glad to be in possession of such a rare piece.