The scratches under the mount don't seem like a serious matter, though they shouldn't be there on a new barrel. Probably there from something going wrong during the installation, though I can't quite see what would cause it. If it was there before the installation and without the base covering it up, they wouldn't have been able to ship it as a new barrel.
The brass is another level of problematic...it's not by any means ready to load or shoot. If they simply noted that it needed to be trimmed and fireformed (as is the case with most any brass we buy) , it would be perfectly reasonable but it shouldn't be sold as finished brass.