By Angus MacSwan LONDON (Reuters) – Decades on from his days as an angry young rocker, a role in a Hollywood movie playing an ageing musician struggling to make a comeback has helped give a new lease of life to Graham Parker. In the movie, Judd Apatow's "This is 40", the bid fails. In the real world, however, things are going pretty well for the 62-year-old London native. He's brought out a well-received album, a documentary and a concert film with his reunited backing band, the Rumour. In late October they play their first British dates in 31 years. The London show sold out straight away. …