I'm a younger guy, but I know I try to pick my outfit carefully when going for an interview. I don't have a totally different interview wardrobe or anything, but I pay a little more attention to matching colors and generally looking more put-together.
You may not even need to get your kids to dress you - just find a friend your age who cares about fashion some to help. Even if you think you dress well, having someone else check you over or make small suggestions can help.