I would need to check, but I think the Official IRA would be, seeing as they went on ceasefire in 1972 and mostly fought with Provos and the INLA after that. The estimate seems to be 57 killed by the OIRA, 22 civilians among that (22%). Provos are around 508 (29%). Another source puts that at 644 (36%) though 61 of those are former security forces so IMHO valid targets