Going back to the propellor at the Hoverport, I think it would have been a fitting tribute to have re-mounted on the seafront. However, a little snooping tells me that the pylon has been donated to The Hovercraft Museum at Lee-on-Solent by DHB providing they can remove it and pay for transportation. It is heavily corroded into the base and this will be an expensive process.
If they can arrange it, the plan will be to mount it on their BH.7 Hovercraft to complete it to its former glory. If Dover has to lose it, at least we can be reassured that it's going to a very good home and a worthwhile cause.
The BH.7:
http://www.hovercraft-museum.org/n15_28.html