-the server (demo) is called RDDR1°HANGOUT_SERVER. i see it on LFS World, but i dont think you can see it on the master server. i also dont think that you will connect after clicking the join link because it says "ClientConnect : connect failed"
The fact that you can't connect isn't significant and highly depends on the firmware of your router. The long and short of it is that because you're in the same network as the game when you click the server in the list you're telling it to go out and connect to your external IP, but because you're port forwarding on the external interface only the router doesn't know what to do with the incoming connection as it sees it for itself.
Sorry if that explaination is complicated, but thats about as simple as I can explain it without just saying "its a loopback effect".
Ideally when you connect into a server on the same network as you, you use the LAN ip of that system.
The fact that you can't connect from the in-game list, since you're on the same network, is irrelevant. You don't use the in-game list.
This also doesn't mean that it isn't working.
John, I appreciate that you're after answers but we're done nothing but go round in circles. You really need someone in person to talk you through this stuff, because clearly trying to explain it in text, over the internet, isn't working.
If you want to carry on discussing it then I'm happy to, but I don't think we're going to get much farther. Now thats probably my own fault, and I freely admit I'm not the best person at explaining things sometimes However, please understand that I can't answer every question you've asked because I literally don't know enough about what you've got setup so far, what software you're running, what firmware you're running on the router, etc. There's also the door knob factor where we'll never get that missing bit of information until you you're on the doorknob, about to leave