I just purchased a zt 0620 off of a member here and afterwards while looking over the pics of the knife more thoroughly I noticed there is no serial number on the blade. I contacted the seller and he said the person he bought it from previously had it rebladed, and that zt won't put a serial number on a knife that's been rebladed so people wouldn't think that it's new. I've never had an encounter like this before, and am a little worried that it could be a fake. Any input would be greatly appreciated. Thanks