He doesn't have that typical cookie cutter show line look, so it's possible he's from working lines. Without a pedigree, it's just a guess though. Never heard the comment about the tail, but I'm sure that's not an indicator if the dog is working lines.
34" is one huge german shepherd. Is that being measured at his withers to the ground? I don't think I've ever seen one that big in person.
He also looks like he's lacking muscle in his rear legs. He looks to be in ok shape weight-wise. Just looks to be lacking muscle tone, but it could be the age.