There is a similar 16' dish sitting unused at a local hotel in Roseville, CA. Not sure of the surface accuracy on this vintage. Would the large reflector even provide increased performance? Many of these were installed prior to 2 degree satellite spacing and don't do well with the tighter spacing. I am sure that it cost a fortune when new, but wouldn't mess with it now. It weighs a ton and would be an incredible project to motorize.
I would look for a more modern product. There are many 3 - 5 meter dishes (many motorized) out there that are sitting unused on commercial buildings. Many of them are TX/RX, so are built to very strict specifications and are very high quality builds. If you have the space, wait for the right one. Check with a broadcast equipment broker. Often these larger dishes can be had for the transportation cost.