My guess is they are large date. There should be a gentle curve in the top of the two. Top loop of the 8 is also smaller.
Regular dime weight is about 2.27, copper weighs 3.11 and the new zinc cents weigh around 2.5. 1968 should weigh around 3.11. 2.97 is close enough.Just wear from age.
Your coin would not have a copper color nor would it have all the letters on the coin. Just a regular coin with normal wear.