I picked up a new lens today. The end of the lens says 35mm, but it's size, weight and field of view are telling me 135. well with a littel research it is in fact to no surprise a 135mm lens. there is no mistake in reading the number, there is no 1, so it's not like it's worn off or scrached out. but it dose show some signs of having been taken apart. My question is: is this a manufacturing error by Canon or do I have a frankenstine on my hands?