I'm not at my bike now, but the '78 is different than the rest. I don't have a clear picture but maybe you can see in this.
There is a motor mount that also holds the clutch cable. The little bracket for the stop switch gets bolted with the motor mount. The spring then goes on the inside of the frame and hooks on to a notched "lever" that is shared with the brake rod that actually pulls the brake arm on the hub.
Hopefully this drawing helps. My handwriting sucks, sorry, haha.
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1978 Honda CB550K