I'm not sure what kind of swing arm that is. I bought an 86 with a couple hundred hole drilled in the frame. I think he wanted to make it lighter, or maybe he had a death wish. He was on track for both.
I sold all the parts except the swing arm and the frame. Swing arm for me and the frame for scrap (parts money).
I love the round carrier. If I have my way, I'll never use the box carrier again.