For sale is a four-valve Conn double bell euphonium, front action, with fixed upright large bell and removable forward facing small bell.  The serial number (238***) dates it to 1926.  The instrument is in overall good condition, with tarnish, plating wear, and small dings and scratches throughout.  It was rebuilt at some point in the past, so the valves have good compression.   The instrument comes with a custom made Altieri gig bag in excellent condition.   This particular horn is definitely more of a player than a collector’s item.  It is without a doubt the best playing double bell euphonium I’ve played (and I’ve owned and/or played several).  Both bells have excellent intonation, which is unusual for a double bell—in fact, the large bell plays better in tune with itself than my regular compensating euphonium.  It has a lovely sound and easy response, and with a “modern” mouthpiece it can sound very much like a contemporary large bore instrument.  There are a number of small modifications that I’ve made to it while owning it.  Both main tuning slides have been shortened, to correct the flatness that comes with using large, modern mouthpieces (I used a Doug Elliot equivalent of a Wick SM3 with great success).  The leadpipe has been moved to a more comfortable position.  The metal valve guides have been replaced with nylon guides, making them much quieter.  The valves have been precisely aligned using brass washers and o-rings.  A spring loaded tuning “kicker” has been added to the third valve slide, which is completely removable if desired.  Likewise, weights have been added to both main tuning slides and the fourth valve bottom cap.  I found all of these additions of mass to improve the sound and response of the instrument, but they are all easily reversible. Most double bell euphoniums are interesting as historical curiosities, but play very poorly.  This one plays exceptionally well.  Please feel free to ask any questions.  Thanks for looking!