Elevator balance weight question

[gregc]

During a pre-flight today I heard a little knock when moving the elevator. Further investigation indicates that the lead weight is moving around a little. The plans just show a couple of tabs to secure the lead. I'm pretty sure the kit version is a little different in that there are triangular sheet metal pieces on the top and bottom. I don't remember if there is a piece on the aft side that encapsulates the lead or not. If someone has an uncovered elevator and can tell me what it looks like it on the aft side it would be helpful. See the blue arrow on the photo.

If it is possible that it could slide rearward, my current thought is a couple of screws where the red arrow is to hold it in place. Thanks
elevator_weight.jpg