Marc....
Having been born and bred in Leeds, I can assure you, that Lanchichor or any area that sounds like it, do's not exist. I honestly think it is Lancashire.....If Mary still had her Lancastrian accent, it could have been interpreted as Lanchichor.
Incidently. There is a Thomas and Mary Lucas, still living in Leeds, on 1841/1851 census. Could this be the couple who married in 1802 ?
JeannieR