Hi Wheelie,
I can see in the Master Server logs that you've tried ports 80, 81, and 800, which is good. The way to set this up in your router is to forward that port (TCP, if you have a choice in the router, otherwise it'll do TCP and UDP, which is fine also) to the machine running FSHost. That way, when the Master Server tries to connect back to you (or more importantly, when other players try to connect to your FSHost), it/they will first connect to your router, which will then forward the incoming data to FSHost. Without that forwarding setup, the router will just "eat" the data and FSHost will never see it.
Try forwarding whichever port you're using to the FSHost PC (195.168.123.165) again and see if you can get it working that way.
Thanks,
Russell