If I were guessing, I would say that the wires coming out of the arm are original. I don't know anyone that would rewire a tonearm with that sort of wire. But then it also appears that someone added the aftermarket RCA jacks, so who knows how the color coding was used when the jacks were wired in. Easy to say, but if it was me I would follow the recommendation made earlier to rewire the arm and add the Technics arm tube and collar. You would have a fully tested arm, and clear wiring instructions. If you haven't already I would also use appropriate wire to address the ground points on the table.
