Altough I quite agree with what Obi Wan had just said, there are two tings. One HMS Bulwark in some part of her career carried the letter 'O' not 'Z', and HMS Albion was 'O' before being 'A'. AFIK HMS Ark Royal was allways 'R'
HMS Albion -'Z' is clearly shown on the front of the flight deck.
As for HMS EAgle I belive you were right and she carried the letter 'E' from 1970 at least.
I gave the correct dates and letters based on photograhic evidence and I also have the full set of Neil McCart's books on the lives of these carriers!
Centaur completed for first of class trials with axial deck and code letter L 1953. Oncompletion of trials immediatley taken in hand for modification with 5 degree angled deck; commissioned in 1954 with deck code C. refitted 1956-58 with two BS4 steam catapults and enlarged island (starboard side). Refitted with type 965 AKE1 radar on new foremast (taken from reserve weapon class radar picket DD!) 1963. Paid off 1965 for use as accomodation ship after a career barely 10 years...
scrapped 1972.
Bulwark commissioned in 1954 with deck code B, and kept it all her life, though from her first commission as a Commando Carrier in 1960 to paying off into reserve in 1976 she wore no deck code. The helicopters assigned to her did carry B on their tails and when the 'Rusty B' recommissioned in 1979 she once again had B on her deck. She never had 'O'. paid off 1981, scrapped 1984.
Albion commissioned in 1954 with deck code Z, changing to A around 1958. No code worn as a commando carrier. Paid off in 1973, scrapped faslane.
Ark Royal commissioned 1955 with deck code O, changed to R in 1958. Not painted on deck from 1973 onwards as she was the last fixed wing carrier, thus she could not be confused with another carrier from the air. Paid off 1978, scrapped 1980.
Eagle commissioned 1951 with axial deck and deck code J, refitted with 5 degree deck 1954, deck code changed to E 1957, rebuilt with 8 degree deck, two BS5 catapults etc 1959-64, paid of prematurely 1972, scrapped 1978.
Victorious recommissioned 1958 deck code V. paid off 1967, scrapped 1969
Hermes commissioned 1959 deck code H. retained throughout her RN career. paid off 1984, sold to India 1986. New deck code V (Viraat).