I was heartened to see that so many relative youngsters are involved in the model A hobby, but there are still a lot of us oldsters, too. There must be a lot of Model A people out there with artificial knees, hips, and/or anything else that can be replaced. I'm wondering if, among those of you who have had replacements of one sort or another, there are some things you just can't do any more to work on or maintain your A or if there has been no effect on your ability (in this respect!) at all.