The Waffle Iron Bases were Japanned, not enameled per se...
If you are seeing Black, that would be japanning.
The bases of most Waffle irons... most of the japanning is severely compromised, so I generally remove the remnants... lye bath will help remove it... and then again, sometimes not... ::) ::)
Old japanning remnants can sometimes present a real challenge.... that may require the Zip Strip and/or the auto detailing pick set...