I have a few old German pipes from my step-father that have wooden stems. There were cracks as you say in your post and this is how I fixed them. Get a nontoxic wood glue, Titebond is what I use, dab it on a Q-tip with the cotton broken off so you are using just the stick. Rub the glue into the crack, do this a few times. let it dry for a day then run a knife blade LIGHTY down the crack, you only want to indent the seam. Then get any wood sawdust, the finer the better, like oak, maple or poplar, do not use pine it will stain too fast. Then run the glue again 1 time and push the sawdust into the glue. Dry for 2 days and then sand only to take the extra glue off the stem and stain as dark as you want. The crack will disappear and no one will ever know. Presto, a good draw on the pipe.
