So scrap generally means "to fight". It is frequently used in past tense rather than in proactive terms, however both are completely acceptable. In my experience in Georgia, this is a term native to Savannah - i've never met a non-Savannian who knows what it means, but this is confined to the state. So i'd attribute SAV as it's origin. Plus, it's SAV-home of Camouflage (the crazy rapper who was killed a few years ago... and who rapped about SAV).. who would expect less for the vernacular.
"My brother and i used to scrap alot when we were kids... but we're tight now"
"You wanna scrap??!?!?"
"Did you catch those two girls scrapin' in the parking lot?"