I would suggest getting a
VAM book and check out the pictures of the mintmarks for each year. Not necessarily the positioning, but the size and style. (Some have large CC, some small, some close spaced, some wide. Sometimes the left C is higher, sometimes the right etc.) Most of the fakes do not get the size and style right for the year (Typically they will use the same reverse die with multiple date obverses. So if you see say an 1881 CC with a mintmark style only used in 1878, well guess what.)
Most of the CC dollars do not have too many reverse dies. It should be fairly easy to make up a "cheat sheet" of flip book for each of the years. If you are looking at a CC dollar and it doesn't match the size, style, and positioning for any of the dies listed on your cheat sheet for that year...