I'm studying the Albinoni - Giazotto adagio (Ricordi score) and have come across a term I haven't seen before.
The organ part begins with "O.E. p dolce". What does O.E. mean here?
Later instructions include "Manuale" (I understand this one

and then O.E. Rip. (Rip. I would believe is likely "ripieno, i.e. full")
Additionally, if anyone has recommendations for any free or reasonably priced sample sets that are particularly suitable for this piece, that would be welcome.
Many thanks