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All cents issues from the years 1959-2008 have the memorial reverse. And yes, they will all have the FG on them, representing the initials of Frank Gasparro, who designed the reverse of the Lincoln Memorial Cent. All Lincoln Cents 1958 or older carry the original "Wheat" reverse, which was designed by Victor D. Brenner who also designed the obverse. Of course, in 2009 the Lincoln Cents carried a set of 4 different reverse designs to celebrate the 200th anniversary of Lincoln's birth (as well as the 100th anniversary of the Lincoln Cent), and then from 2010 to the present the cents have the new "Shield" reverse.
Hope that helps!