If it really is oil escaping then you need to be careful. If it gets bad enough, it can lead to a turbo runaway where the engine runs on its own oil, followed by a rapid unscheduled disassembly..
You probably have a (slight) exhaust blow near each witness mark, easy to pinpoint with a length of tube, one end held to an ear whilst probing around with the other. Then a case of remaking that joint (if possible) or replacing broken component.