I finally got the turbo to spin freely by using a wireless drill and a socket wrench on the nut holding the fan assembly together with the engine shut down of course. I ran the engine twice and seems it was stuck probably salt water ingress as you said.
I did have an accident caused by over cranking and water coming into my carter. I did flush the engine six times and the oil seems to be clear from water now.
I tried getting the kit in eBay but one vendor I consulted told me the kit they sold was maybe not compatible with this turbo unit. I sent you the information concerning our engine in case it helps to locate the part.