Londoners rhymes with:
gardener's, gardeners, hardeners, schuldener's, commissioner's, commissioners, commoners, conditioners, confectioners, coroner's, coroners, examiner's, executioner's, executioners, falconers, fasteners, foreigners, foreigners', fresheners, gardener's, gardeners, hardeners, listeners, mariners, openers, parishioners, pensioners, petitioners, practitioners, prisoner's, prisoners, prisoners', probationers, questioners, reasoner's, schuldener's, stationers, sweeteners, vacationers, vacationers'
Londoners sounds like:
landmark, landmark's, landmarks, landowners, lindmark, lindner's, lundmark