I’d not heard that song before, but yes the marching melody, and the drum breaks, are very similar to Copperhead Road. However, many Irish folk and rebel songs were written to traditional Celtic fiddle tunes, and it would seem likely that that loyalist song was too. Without leafing through my copy of O’Neill’s 1200 Irish Dance Tunes, I can’t identify it as yet, but there must somebody out there with some fancy software that can pinpoint it precisely much sooner than I could.