help! need gm part no. id

ok, trying to clean out some of my junk in the garage. found this nos or early take off rocker molding. it has 66 vette written on the wrapper.but i,m not a vette person. was hoping somebody could tell me if it is or not.here,s what,s on the wrapper.
1-481539
gr,08,304
mldg,u,eg4
thanks bob

 

1970-75 (maybe later too?, I only have a 1975 parts book) Camaro RH body sill molding

 

thanks squirrel,