When I was younger, I saw surface-mount porcelain receptacles like these being sold in local hardware stores here in New York.
The one I have is made in the U.S.A. by the old Eagle Electric Mfg. (now Cooper Wiring Devices).
Another one I have lying about is imported from People's Rep. of China.
It can accomodate a roun-pin plug (4-mm pins) like the ones used in Europe or a standard flat-pin plug.
Were round-pin plugs ever used in the USA, or is this just a universal type socket that can be sold in any part of the world?
The hardware store owner said they were called "barn receptacles". Anyone else ever seen these?