I recently received additional information which comes from The Search for Missing Friends which is an eight (to date) volume series of Irish Immigrant Advertisements placed in the Boston Pilot Newspaper searching for lost friends and relatives - it is published by NEW ENGLAND HISTORIC GENEALOGICAL OCIETY - BOSTON - and is available in some libraries and FHC's -the series contains thousands of references to names, countries, counties, parishes, townships, etc and is indexed and covers time period pre 1830 to 1920.
It appears to be quite useful as a tool. the following information comes from this source:
8TH JAN 1855: Information wanted of ROBERT FLAHAVAN, a boy 6 years old, from AHANAGRAN, parish of BALLYLONGFORD - co KERRY. , a son of JAMES FLAHAVAN, who lived in TULLAMORE, parish of KILCONTY, co KERRY. The boy's mothers name is ANNE SCANLAN - He sailed from CORK for QUEBEC on the 29th May last. He was accompanied from CORK by JOHN MCMAHON nd MARY FOLEY - JOHN MCMAHON took charge of the boy after landing - since which no account has been had of them - Information will be received by his father JAMES FLAHAVAN, DELAWARE P.O. DELAWARE CO. OHIO.
Does any of this sound familar to anyone out there searching the Flahavan/Flavin/Flavahen lines?