According to his obituary in The Times, Derek Coombs attempted to secure the rights to film Casino Royale, Live and Let Die, Moonraker and Diamonds Are Forever, presumably in 1956 or early in 1957 before the publication of Fleming's fifth novel, From Russia, with Love. Peter O'Toole, Derek Coombs' future brother-in-law, had just begun his acting career (his first television role was in 1956, and he would not make his film début until 1958), and naturally Coombs saw the role of Bond as a vehicle for him.
The story of Ian Fleming's efforts to bring his creation to the big screen is a convoluted one, involving rival deals, many false starts, protracted negotiations, and not a little naivety on Fleming's part. The key facts, however, are these. Following publication of Casino Royale in 1953, Fleming's US literary agents, Curtis Brown, were approached by Associated British Pictures and then MCA about film rights, but talks came to nothing. Sir Alexander Korda subsequently expressed an interest, having read the proofs for Live and Let Die (1954), but this similarly fizzled out. Fleming had more luck in 1954 when producer Gregory Ratoff secured the rights to Casino Royale, but negotiations between Fleming and Warner Brothers' producer Stanley Meyer for Live and Let Die and Moonraker soon stalled.
In 1955, two offers were made for Moonraker, one to Curtis Brown from John Payne, and the other to Jonathan Cape from the Rank Organisation. Neither was successful. Another offer was received by Curtis Brown in 1958, this time for Dr No, which had not been long published. Kevin McClory entered the picture the same year, and attempts to produce a film of what would become Thunderball (1961), would have long-lasting and serious repercussions for Fleming's creation, his health, and the later EON film series. There was another film offer in 1959, this time from MGM producer Maurice Winnick. In 1961, Harry Saltzman won a sixth-month option on the Bond books, but failed to gain any backing to produce the films until he was introduced to Cubby Broccoli. Dr No was released in 1962 and the rest, as they say, is history.
Quite how Derek Coombs fits into all this, if at all, is unclear. Ian Fleming, usually via Curtis Brown or Cape, no doubt received many approaches from would-be film producers, some (like those above) being more serious than others. Possibly Coombs' offer was quickly dismissed as unrealistic, or perhaps his plans barely left the drawing board; The Times notes that Peter O'Toole was not interested in the project.
The obituary adds, interestingly, that later, when Kevin McClory spotted Derek Coombs in a restaurant, he sent Coombs a magnum of Champagne to thank him for Bond. This suggests that Coombs' attempt to acquire the rights to film Bond was serious enough to attract the attention of rival film-makers. Nevertheless, the incident is curious. Coombs' efforts pre-dated McClory's (unless Coombs made his approach in 1958/9), and anyway McClory did not have an exclusive right to film Bond (Ratoff still owned the rights to Casino Royale). There was more than enough Bond to go round.
More information is required, but it would seem that Derek Coombs' attempt to film Bond has marginal significance. In any case, his bid for Casino Royale would have failed immediately because of the rights to the book already secured. In the late 1950s, Peter O'Toole was very far from being the first cinematic Bond.
Lycett, A, 1995 Ian Fleming: the man behind James Bond, Turner