I don’t know how they do it. It would be like digging up a grave, pulling out the skeleton, making a Frankenstein, and then animating it. Almost like 90% new manufacture, 10% ghost in the shell.
I had that discussion with a docent at the D-Day Museum in New Orleans several years ago. They were “restoring” a Higgins PT-Boat. It’s now operable and currently berthed on Lake Pontchartrain.
They were replacing all the hull planking, among other things. I asked when does “restoration” become “replica?”
He didn’t have an answer.