If you are in central London, the Nags Head at Convent garden is a McMullens pub,so you will get your fill there.Cheers for that I live in Spain havent been back for years, due home soon so will be sure to have a pint or two of Country. McMullens and great memorys of my grandad. ( smiley face)
Its a Hertfordshire brewery,so you have to head to east herts to find other pubs.There was a McMullens pub in Tufnell Park,but that closed down a few years back.