You will easily find the Guilcagh as it is marked on the map - however a quick search through the telephone directory (Post codes Residential for 2002 which had them arranged under Post towns) indicated no post code either for The Guilcagh or for Laurel Cottage. (I may have missed them though but I have no Larel cottage, Andreas in my place names data base)

The Teare's farmed Guilcagh in the 1890's (see 1894 Brown's directory) so assuming they owned it then, as all deeds of sale have to be registered you can try first the Manx Museum list of deeds or the General Registry - the former are indexed by seller as of yet the all-Island on-line register is not complete but I think Andreas was going to be one of first parishes completed.