Blondie,
You should try and get your hands on a copy of Mayo's Lost Islands - The Inishkeas by Brian Dornan. It has extensive information about families on the islands in the 1800s. Plenty of mentions of Lavelles in it! It's a pretty interesting read anyway but for anyone who has ancestors from the Inishkeas it should be compulsory reading.
Also back in 1895 a Dr. Browne did an ethnographic study of the Mullet and the Inishkeas. It's a study of the people basically. If you want send me a message and I'll send it onto you. You never know, one of the men detailed in it might be an ancestor.
Happy Paddys Day!