It is a standalone machine.
I saw that KB article previously however I am unable to find a Repokeys.ini file on any of my servers so I can not copy it across.
From my understanding of the article (I may indeed be wrong) the Repokeys.ini file should be on the distributed repository server. However, this (ftp) server again is a standalone server in the DMZ and so not managed via ePO. If this is correct then that would probably explain why I can't find the .ini file.
The repokeys.ini file will actually be on another client machine that is managed by the ePO server, rather than in a repository - it will be in the %programdata%\McAfee\Common Framework folder.