Hi. I too have been wondering where Cuilfhionn is. I'm trying to get a date for when the Highland bagpipes were legally reinstated in Scotland - as an aid to recruitment to the army! The kilt was allowed under the Disclothing Act of 1782, so maybe the law banning pipes was removed then. I read that the Statutes of Kilkenny, banning the pipes in Ireland, was never revoked.
Shakespeare wrote of "woolen" pipes and that certainly sounds like a corruption of "uillean". But I think "cuisle" (pulse, throb), "uillean" (elbow), and "union" (of the drones and chanter)are names which have distinct origins rather than arising one from another. There was a lot of discussion of the subject at IrTrad-L. You can find the archives at http://listserv.heanet.ie/irtrad-l.html and look up the Jan and Feb 1999 entries under "onion pipes" and under "uillean" or do a search at the same site for "onion or union" (minus the quotation marks) since Jan 1999. I recommend the latter strategy, as it will show you the initial sentences of the relevant messages and you can then click on any message that looks promising.