If the mouthpiece has a serial number on it, then most likely it is the same as the current Jazz Model 6M. That model has been available since the 1980s. They are still made the same as they were in the 80s...molded and completely handcrafted inside and out. Early ones were marked, "Bilger-Morgan". The Jazz Models are not marked "Jazz", but have the Morgan logo hand-engraved on top, a serial number and 6M on the shank. The Jazz Model has a standard size alto body whereas the Excalibur Model has a streamline body and a metal ring on the shank.I have an older Morgan 6M. There is nothing indicating Jazz. Is this the same as the current Jazz 6M model?