I believe they still shroud them. And I vaguely recall reading about a museum that received a retired prop design; they had to vertically mount it for display p

I believe they still shroud them. And I vaguely recall reading about a museum that received a retired prop design; they had to vertically mount it for display partially underground, as the Navy wouldn't let them cut the bottom blades since there was something still secret in the construction of the casting. My guess is it was hollow like jet fan blades