If it's not closing up enough to take a metal repair band and the lines of the pipe don't lend itself to a nosewarmer proportion, I wonder if you could fit/bond a contrasting section of wood (maybe reinforced with a metal tube) that would make an interesting bridge between where the crack ends and the stem plugs in, keeping the original length. You could get creative with the bridge piece. Pipes are often seen with bamboo parts there (varying in degrees of success). Inlays as thin accents could be interesting if done tastefully.