This is a fantastic 143k ‘Sanborn’ model period MK VI alto with the “Mark VI” stamp on the side of the body.  These are/were said to be specially good, but I’ve found most of the 140k altos to be great anyhow so I am not so clear on that part.  This horn is in very nice original (USA lacquer and engraving) condition with only one reattached low Eb Key guard foot, that is a very common situation with vintage Selmers.

The pads appear to be quite recent and seated nicely with a verifiable popping at the closing of the keys.  The resonators appear to be nice quality domed nickel plated brass which is a bonus.  The neck is in nearly perfect condition and is model period correct and without a serial number as the 140k’s were made.