Found the CBF 1 you mentioned when I pulled up some pictures from my collection. Cast into the front surface by the casting date . You mentioned that you were looking at a stamped date so I'm guessing you were not referring to the casting date that is on the face also of the early style pumps
"CBF 1" I believe has something to do with the supplier. May/most of the Thermactor parts were not made by Ford but by suppliers and sub contractors like allot of each car
Never have had a need for a pump valve. Guess I would start by finding one of the places that rebuilds them, likely available since some of the parts houses have been altering late model pumps by drilling holes in the cases and adding them, only to sell them on Ebay aas originals. Sometimes