The numbers of interest would be on the top of the frame rail. Those on the side are the mfg. number and date, the top of the frame rail will have the partial VIN. However, the partial VIN is of no use in determining whether it was born with the SS option or not; a match would only mean the frame is original to the car. But, see http://chevellestuff.net/qd/frames.htm for the locations of previously found partial VINs on the frame.
See http://chevellestuff.net/1969/69ss.htm for more on the 1969 SS option. Does either the engine or 4-speed have a partial VIN stamped on them? If they are original to the car and match the car's VIN, that should suffice. Dale
