I just ran across a new hands free holder from Piknboard.  I said  goodbye to that neck thing forever.  This slick giz holds two harps, mounts onto the end of a sm57 or 58, and and rests in the mic clip.  Hands free, two harps.  Now I can get the missing fourth or fifth, depending on if you are playing straight or cross harp.  They have a slick way of mounting both the harp box and a vocal mic on a boom.  This has simplified my life considerably.  I don't think they are even advertising it yet, (I got a prototype from a partner in Utah)so you might try contacting them.