I was sent this photo today, and although I know it's a Gulfstream I, I cannot find its registration in any database that I have access to. Can anyone provide the serial number and any other details on this aircraft? It was taken in Cleveland in the early 70's, and any registration search comes up with the wrong aircraft. I assume the registration is N20S (two-zero sierra) but I tried two-oscar-sierra as well to no avail. Any help much appreciated! Thanks!