Gemini sst

Have recently been asked to work on a old Gemini sst (orange in color) I believe it to be a 50cc. I need a complete throttle cable for it and wanted to see if anyone out there had one that I could buy. I believe that the Shin San Tong Gemini was only imported from 1969 - 1972 and I have know idea what year this one is. Will the year make a difference? And is there anyway to tell the year without the papers on it?