My 25 year old normal female shed a couple of days ago, it pretty much all came off in about 4 pieces.

http://www.colin-java.co.uk/pics/scales.jpg

I noticed some scales look like they have haven't shed, in the pic in the green oval there's a blob in the middle with like a V shape.
And to the sides of the at some scales look discoloured.

I rubbed them with a bit of water but it makes no difference.

Is this like an age thing, like how people get blotches and stuff as they get older?