Here is a really beautiful historic Super Action (SBA) also, 43xxx, all original lacquer finish and US engraving.  The pads are kind of old and it will definitely need some regulation if not some pad replacement.  It is currently not playing great, just a bit leaky, but given how these were made and what they are, it’s going to be phenomenal.  The neck is original with the matching number as well. The key action just feels wonderful in the hands. The MK VI is obviously very popular but these earlier SBA altos have a sound and response that is absolutely amazing.  This one is ready for a custom beautiful setup.