LONDON — WT2, the low-budget arm of Working Title, is set to produce “Jonjo Mickeybo,” the directorial debut of Irish writer/helmer Terry Loane, starring Julie Walters and Ciaran Hinds.The pic, which starts shooting Wednesday, is the story of two boys from each side of the sectarian divide in 1970s Belfast, Northern Ireland. They flee to Australia to escape the prejudices of their homeland and to live out their fantasy of emulating their heroes, Butch Cassidy and the Sundance Kid. It’s adapted by Loane from Owen McCafferty’s play. Gina McKee, Adrian Dunbar and Susan Lynch co-star. Mark Huffam for WT2 and Mike McGeagh for Belfast outfit New Moon Pictures are producing, with Stephen Daldry and WT2’s Natascha Wharton taking exec producer credits.