Most of the letters of recommendation that my son received were addressed to "To Whom It May Concern". He had all of his letters sent directly to him, not his OSO. After he received all of the letters, he hand delivered all of his recs to his OSO. As we all would hope with letters of recommendation, his recs provided input on what a fine person he is and how he will be a fine leader of Marines if selected. After the letters were delivered to his OSO, his OSO gave him a one-page Xeroxed "form" for him to send to those who wrote letters. It was basically one of those "typical" forms where you rank certain "characteristics" of the candidate on a scale of 1 to 5 (poor to excellent). Actually it wasn't 1 to 5, more like rankings such as always, most of the time, occassionally, rarely, not observed. (I hope you understand what I'm trying to say.
. My son mailed off the forms to those who wrote letters and had them fill them out, sign, date, and return them to him. He then delivered them to his OSO. It would probably be OK to have everything (letters and forms) delivered directly to your OSO but the only way to know for sure that all the letters and forms are received by your OSO is to have them sent to you first, then hand deliver them to your OSO.
By the way, my son was accepted for OCC 184, SNA, out of the Dallas, Tx office.
Good luck to all of you. Most Americans have no idea how high the standards are for one to be accepted for OCC (OCS). Even to be considered is quite an honor....although, certainly, being accepted makes you feel much better than being considered but turned down.
Semper Fi Dad