Thanks, will write up what I've found after a bit more testing. One quick extra, you don't have the outgoing port allowed in the firewall settings for Ubuntu's

Thanks, will write up what I've found after a bit more testing. One quick extra, you don't have the outgoing port allowed in the firewall settings for Ubuntu's apt-key to add new trusted keys, using the hkp service (port 11371), it would be nice if you could add that.