I have just looked up 'Wifi Beacon Box' and am none the wiser what it does.
Lots of folk around here are ante powerline. I have used it for fifteen or more years in a flat that is 125 years old. Solid walls and rubbish wiring!
One lesson learned is how much it has improved over the years.
Let's see what the ante powerline gurus suggest. My suggestion would be that if your powerline kit is old then try upgrading to something like the Devolo Magic 2. If you buy it from Amazon and it does not work you can send it back!
I get 200 mbps and that is plenty fast enough for me. Do you actually need 950?