The stuff we know today as Carbon Fibre Reinforced Plastic (CFRP) is based on a 1963 patent from the RAE at Farnborough as far as I know. CFRP applications in civil aviation go back to testing done in the late 1960s and early 1970s, with the first CFRP elevators being tested on a 727 in the late 1970s (see here:
https://ntrs.nasa.gov/api/citations/...9840019654.pdf). No doubt applications in the military world may go back further than that, but my money would be on the use of glass-fibre based composites in the F-4 (with honeycomb cores, civil designs from the late 1950s use these same materials), with the name CFRP being used incorrectly.