Experienced media investor Mickey O’Rourke is “doubling down” by becoming a significant investor in Joe Media Group in both Ireland and Britain. David Sefton, the founder of Anglo African Oil & Gas, is exiting the business. O’Rourke will join the senior leadership team in Joe Media Group alongside existing managers John Quinlan and Paul O’Donoghue. Quinlan and O’Donoghue said an email to staff: “The investment will be used to support further acquisitions of brands in the social publishing space and to add further verticals as we look to become a ‘one-stop shop’ for platforms, media agencies and brands with our…