Rex Tucker directed the Doctor Who story The Gunfighters and contributed to the lyrics of "The Ballad of the Last Chance Saloon". However, he did request that his director's credit be removed from the closing captions of "The O.K. Corral" following a disagreement with Innes Lloyd over its editing. He was credited for all the others.
Tucker also had a significant impact upon the very origins of Doctor Who. Despite a lack of screen credit, he was the programme's first producer. Appointed in May 1963 as an "interim" or "caretaker" producer until Sydney Newman could find a permanent replacement, Tucker was also, for many months, the director of An Unearthly Child. Had the show been filmed for its original 24 August 1963 launch date, he would have been Doctor Who's first director.
On 28 May 1963, he became the first in a very long line of people to send a memo to his superiors about the unsuitability of Lime Grove Studio D for Doctor Who. His memo to Donald Wilson worked, inasmuch as it got Wilson, Ayton Whitaker and Ian Atkins to accept the word of an experienced director that Lime Grove simply didn't meet the technical requirements of a programme like Doctor Who. It also resulted in Wilson supporting the notion of Riverside Studios as an acceptable substitute, should studios at Television Centre prove unavailable. In the end, of course, Lime Grove would be used, but Tucker's initial memo had the effect of getting important players mobilised in the fight for facilities. It also resulted in what would become the basic facilities priority of the 1960s: TC first, then Riverside, then — as the very last resort — Lime Grove.
He also began the process of staffing for the show. He was the original point of contact between Doctor Who and Tristram Cary. Though Cary would ultimately not provide the theme and incidental music for the first serial, he would be in place to score The Daleks and The Dalek Invasion of Earth, cementing some musical punctuation into the fabric of Doctor Who. Tucker would also bring back Cary for The Gunfighters.
Tucker was also involved in initial casting. He was the first person to offer the role of the Doctor to an actor. Had Hugh David accepted, Verity Lambert would have been saddled with a star she had not chosen. He also held casting sessions for the part of Susan and Miss McGovern, a character who would become Barbara Wright. As with the Doctor, he was not able to select an actor for either of these parts.
He was also responsible for reducing C. E. Webber's contributions to early Doctor Who. He rejected Webber's The Giants, the first of three attempts to write a story about a miniaturised TARDIS crew. This story would have been the programme's first serial, the one Tucker was slated to direct. Instead, Donald Wilson and he tapped Anthony Coburn to bring his story, then called The Tribe of Gum, to the first position, but to rewrite it so that it incorporated some elements of Webber's first episode.
He was known to have worked out a production schedule for the first serial that would have allowed recording to begin about 19 July 1963. On 1 July, however, Donald Baverstock's office informed the Doctor Who office that the series would not begin transmission until 9 November. This meant that the recording of The Tribe of Gum, as it was still known, would largely happen whilst Tucker was on his scheduled vacation. For a brief time, he was assigned to the second story and then bumped to the fourth story, which was, at the time, the Terry Nation script; he might have become the director who introduced the Daleks. It is unclear, however, what preparatory work, if any, he did for that serial. By the time he left for holiday on 30 August he had begged off Doctor Who and been re-assigned to Madame Bovary, a serial on which he would again be joined by Tristram Cary. (REF: The First Doctor Handbook)
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