The Type 1 1851-1853 no outline on star. The Type 2 1854-1858 three outlines on star. The Type 3 1859-1873 two outlines on star.
Does it really matter? Just try one for as long as it takes then see how it looks if you don’t like it then don’t do the others as long or at all. If they were mine I’d buff them up until they shine, jewelry is supposed to be shiny after all. What’s to loose all the value of them as coins is gone they are worth very little comparatively. Plus they were free so do what makes you happy and enjoy them afterwards. Reed.