Attached is a picture of a mainspring from a watch I'm working on. I took the mainspring out of the barrel to clean and lubricate it but when I was about to put in back in, I noticed it was broken at the arbor end. did I do it, I ask myself? Well, id took the picture before I removed it from the barrel and it looks like it was already broken, but I need a more expert eye to confirm it. I'd appreciate your diagnosis. Thanks!