A friend of mine, David Hollinger, in Mercersburg, Pennsylvania, has
taken apart a large number of pre-1935 players and has stack units,
bellows units and some miscellaneous parts for sale.  Makes include
Standard, Simplex, Schulz, Otto Higel, Gulbransen and Aeolian.
I have posted the list on my website at this page:

  http://www.osbornej.com/content/player-parts-sale 

There is a phone number and email address there for contact.

Thanks,

Joseph Osborne
Carlisle, Pennsylvania, USA