Owners of Edison diamond disk machines could purchase (from other makes
than Edison) an adapter to play "regular" disk records (laterally cut).
Some of these even enabled you to turn the reproducer to play other
brand vertically cut records such as Pathes. These adapters are quite
commonly-found, both at phonograph shows and sometimes on eBay.

I have read that the very last of the Edison disk machines had some
sort of dual reproducer, but I have never seen one.

Jim Canavan
Alexandria, VA
http://members.aol.com/vapianola