Well, the Unda Maris stopface is not original. In fact, only the two O Forte, the T Tremolo and the E Expression stops still bear the originals. The other stops have been "translated" in Italian, using three different styles of stopfaces:
1) Principale 16', Principale 8' and Unda Maris 8', without the ' after the footage;
2) Ottava 4', with the footage written as 4p inside a circle;
3) Gamba 8', with the footage written 8p. without the circle.