Not sure what info you are seeking 
The "C" block is usually a 57 model year.
The "C" heads are usually a 56 model year.
I have seen exactly what you have -meaning an original "C" block with "C" heads.
In my case I believe this configuration came from a 57 Canadian Mercury pickup truck.
The distributor numbers FEK12127 transpose to part number B7A12127D.That is a common 312 dizzy.The 724 on the dizzy would be the date code of manufactor,Feb 1957.
Now my question to you is-has this ever been rebuilt and if your selling it-how much?I may be interested.I am only interested in non-rebuilt engines.
Oldmics