Of course it was a counterfeit battery, no hologram/serial number. I'll get my E50 today and I'll size it up with the fake battery to see how things fit.
I sent the ebay seller a question asking about the authenticity of the battery. I told him the auction led me to believe that it was a genuine Nokia part, when in fact it isn't. Still no response. I'll at least leave feedback stating that it's a knockoff, which should really be disclosed in the auction description.