Not sure what the difference is between years but my 76 side cover emblem has the push on washers with the 4 tabs that grip the emblem stud. I used a jewelers screw driver to gently pry the tabs off the stud just a bit so they would come off (you usually only have to pry two adjacent tabs, not all four.) You can flatten the washer in a vice or pliers and reuse them. The tank emblem has very small inserts that go in the holes in the tank emblem mounting bar. The emblem studs go into the inserts. The stud expands the insert which grips on the emblem mounting bar. The emblem can be gently pried off and the inserts then pried out.
-P.