We would like to download the sources for a private source mirror, but are unable to gain access to the ftp.ussg.iu.edu server. If there is a better way please advise, otherwise we would be willing to be a public mirror.
May be you should try another mirror to download from. I don't see how your intention to build a private mirror can affect your connectivity with ftp.ussg.iu.edu.
Please try synching to another mirror besides ftp.ussg.iu.edu.