There is a small tab adjacent to the rectangular hole on the rear brake plate where the handbrake lever emerges. It has a small hole in it, that appears at one time to have been an anchor point for a spring. However, there is no part shown for such a spring, and I know not where the other end of any such spring might be attached. It's close enough to the handbrake lever to suggest that the two might be related, but I can't find any reference to such a spring. Any ideas? Thanks.