I still have a partial bottle of Aeromaster's Tire Black that I bought years ago, and I'm quite satisfied with the color. After painting the tire, I drybrush either brown or grey, depending on what type of surface the aircraft flew from (dirt or otherwise).
Mike, I tried using Testor's Rubber once before and like you didn't like the results--too brown. I had never associated the color with a Tootsie Roll, but that's a pretty accurate comparison!
Mark