Complex sentence: Negotiations for film rights began as early as 1960, when he was resident in Salcombe, on the South Devon Coast, though it was not produced until a TV movie with Angela Lansbury in 1992.
Split into simpler sentences: Negotiations for film rights began as early as 1960, when he was resident in Salcombe, on the South Devon Coast. It was eventually produced as a TV movie with Angela Lansbury in 1992.