The top button is likely a horn button. The side button could either be a kill switch or turn signals. Hard to tell. These styles of switches are still available from moped parts suppliers like Treatland.tv, 1977moped.com and mopedjunkyard.com (I could be wrong about the URL for that last one). Personally, I like the cleaner look of motorcycle controls, so when I get that far, I will put them on my SB.
Edit: After re-looking at the photo, it could also be the headlight switch.
Paul