There was a recent string about these on MMD.  Check the index.

Try QRS in Buffalo, NY.  You have to ask specifically.  They are not in
the regular catalog.

There was a guy in San Francisco who sold a lot of used ones.  I'm not
sure if he's still alive or his address.  Last info I had was
Leonard's Player Pianos.  I think that's his last name.  Check San
Francisco Yellow Pages.  I have a 10-year-old phone # 415-665-7916.