Posted 02/23/2014 7:07 pm
There are many different variations of this set that were issued. Some were cards you could put the circulation coins in. Some were BU or proof (sterling silver). I've never come across specimen before though. And neither Charlton Vol 1 nor 2 mentions specimen versions. PL was only used up until 1967. For 1968 it was replaced by BU (or NBU on ICCS certificates) although it took a while for the transition in naming to be completed so you can find some older certificates on coins 1968+ that call them PL.
