RC, In my opinion "pure" is a relative term when used in context with a lepomid. At one time there was thought to exist two strains of coppernose in Florida alone, a northern variety located in the panhandle, as well as a more southern variety. Opinions differ as to the validity of that assessment, depending upon what you read, and who you choose to believe.
Factor in regional adaptations and things get more complicated still. THEN, allow for the possibility of genetic dilution due to the mixing of subspecies, whether orchestrated or naturally occurring, and it gets really crazy.
And in the end, coppers are usually thought to be a subspecies of northern strain bluegills in the first place.
Your fish look great to me....I suggest you keep doing what you're doing, enjoy the fruits of your labors, and don't get too hung up on pedigrees.
JMHO.
