You would think Peterson would be able to do it - but it actually is difficult for ANYONE to accurately date them for some reason. I remember talking to 3 different sellers at Chicago last year to date a Peterson and even after consulting 3 different books (one of which was old and falling apart) we couldn't nail down a time frame because of the conflicting insignia on the silver piece. By the way, the Peterson store in Dublin is staffed by only a few people and they aren't Peterson experts, they're just "counter help". So the best guess is just that it seems - a best guess. Good luck though - they are nice pipes.