Cajundad, if it's only little dings (hard to tell without pictures), i.e., the wood was pushed towards the inside, you can quite easily remove those yourself using a wet kitchen towel, and a hot metal, e.g., a kitchen knife heated over a candle. Using steam to raise dings out of wood has been a well-known woodworking 'trick' for probably 2,000 years and many people restoring antiques (and pipes) use it with great success. It's also very safe to do. You put the wet kitchen towel (cloth, i.e., cotton, by the way - not the Kleenex ones!) over the ding and then press the tip of the hot knife against it. It will hiss and steam will start to form at that location. 3-4 Repetition should get rid of most dings. If they are way deep, steam might not fully get rid of them and the pipe might need to be re-topped in addition to the steam treatment. Again, hard to tell without a pic ;-)