More about 16.66 rpm records.  I purchased new, in 1958, a General
Industries 4 speed turntable, which included 16.66 rpm speed.
I believe I purchased it from Olson Electronics, though I am not
certain.  The 16.66 rpm records were for early "Talking Books".
I think that if I look hard enough I can come up with a couple of
them purchased in the late 1950s or thereabout.

Jim Cook