Here are photos of the 2 obverse types (no shoulder fold and sholder fold) and the two reverses(Far Leaf and Near Leaf). Besides the actual extra lines on the queen's shoulder which can be tough to see on a worn coin you can use the obvious difference in the top and bottom of the letters. On the NSF the letters are extremely flared out while on the SF the letters are almost straight. The "I" is a good on to look at and see the difference. The reverse can be easily identified by the distance the Maple leaves are from the denticles. Far Leaf and Near leaf. Here's the NSF, which is rare when combined with the Leaves near the denticles.
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