An early wooden 2 pin plug with unusual side entry for the flex.
Contacts are brass, with a disc of a compressed fibre material.
Flex exits the plug via a small hold in the side.
The screw has rusted, staining the wood and the disc.
The pins are turned brass with the pin separate from the wire terminal so it can be secured into the red disc.
There is no flex grip, other than the wires being pressed against the wooden base by the red disc.
This video features this and several other wooden plugs.