I think I may have figured out what that “extra” piece from the MAC exhaust was for.

http://www.austincaferacer.com/2008/08/mac-exhaust-revisted/

I think know it was to keep the center stand from hitting the chain and the rear brake mechanism. When I took the bike off the center stand I didn’t notice anything peculiar. What I didn’t notice until yesterday was that the center stand was pushing the chain up about an inch and a half. And I didn’t notice that until I was riding the bike and I heard something rattling. Luckily nothing happened to the chain. One of the pieces of the rear brake was slightly scratched though. Needless to say, I felt like a total noob.

First, I removed the tension bolts on both sides of the stand.

It took a swiss army knife and a pair of needle nose pliers to pull out the cotter-pin from the axle thing that the stand rotates on. Next, I tapped on the axle rod with a hammer until it came out the other end. I had to use a flat head screwdriver and a hammer to finish it off.