Yes ... there is at least one one known example of a 1983-P
LMC struck on a copper planchet ... this coin is highlighted on page 75 of the 3rd edition of "Strike It Rich" ...
Many of us weigh our 1983 ... I submit that a scale accurate to 0.01 grams can be had for less than $25 ... and should be a part of your roll searching kit.
Let us know the weight of your 1983 ... 3.1 grams for copper versus 2.6 grams for a zilcoln.
David
Take a look at my other hobby ...
http://www.jk-dk.art