Looks like a VLDS (Very-Late-Die-State) example. On the reverse the missing devices are from a Struck Through Grease issue. No premium for this example as 54% of them look like that when they reach that die state. But you could save it for an Education piece to show the die state and a Struck Through Grease issue. (no premium for this though)
Struck Through Grease for the missing letters on the reverse, the rest of what you are seeing on the surfaces is from a very worn die issue, and 2.5g is the proper weight for a copper plated zinc cent.