Mike, My wife (Asian) and I are in the situation as you. From everything I have read as a UK national, even with dual nationality, you cannot take your wife to UK, unless you are (may have) worked in EU outside UK. However, if you were just Irish, or any other EU National other than British, you probably can.
We went to Gib a couple of times with my Irish passport, I did not mention I had dual nationality, . No problem. Then I wrote to the Immigration in Gib and said I had worked in Spain as a voluntary translator with the Police for many years, they said it that case I could take my wife to Gib. We gave it a go and the guy at the border said even with just my British PP she could go in. He did not ask about working. I tried to show him the email from the Immigration Service but he did not want to look at it, So maybe it depends on who checks you.
I spoke to British Airways about taking my wife to UK using the Irish PP (The Surrender Singh route; http://blogs.kent.ac.uk/eu-rights-clinic/2013/12/08/uk-changes-rules-on-surinder-singh-route/) but they said they would not let my wife check in unless she had a visa.
I believe you should be able to get a Family Permit, which I understand is free. Info here:- http://www.ukba.homeoffice.gov.uk/eucitizens/eea-family-permit/
Good luck, Mike