@engineer,
I haven't read your link yet, but from memory (film and book) didn't they scupper it just inside territorial waters? Any further out and it would have been fired upon by the Royal Navy, I think.
I'll now read your link, but my thought at this moment is that if it
was in territorial waters, then Uruguay's permission should have been sought before any salvage work carried out. Surely at that point any possession and/or split of profits would have been agreed.
I bet you that the enigma machine etc. was taken off the ship before the scuttling.