Just a quick update.
Yesterday I installed RRAS on the server I wished to P2V, then using a local Win7 client machine I connected via VPN to the server (ironically, the Win7 client was a VM itself 
). With the VPN in place, I did a full install of the Standalone Converter on both the host server and the client machine. I then had the server connect to the Win7 machine and set the P2V process going.
9 hours and 58 minutes later it had finished and I now have the P2V'd machine running here on Workstation 9.
It seems the almost impossible was actually possible