Klong25

When you file the claim, at some point they will give you a C & P exam for PTSD.
It would not hurt to let the examiner know you have a PTSD diagnosis from a private examiner...but what is more important is that CAB on your DD 214 and those Buddy statements are Great to have too.
If you do not fall under the 2010 PTSD regulations (available here under a search), they will want proof of your stressor but sure might concede stressor, since you have the CAB.
Make sure the VA has copies of all of your private medical records.
5 Buddy statements- wow...my daughter helped a group of vets who all had experienced the same stressor (Vietnam) and found each other years after the war. One of the vets attached to his buddy statement , a copy of his VA PTSD SC award ,and said this was the same stressor that the other vets experienced too.
Not only did all of them get higher PTSD ratings, or were SCed for PTSD for the first time with my daughter's help but they also all got more awards for the stressor incident...one got the DFC.I rattled this story off before here- she had translated a Vietnamese document they found incountry that held their names and SSA /servicenumbers and they thought is was a hit list.
It was a high commendation for their bravery due to the specific incident from a Vietnamese Officer.
My daughter was a certified Vietnamese linguist ( USAF Intel)
As long as they complied with the brief criteria here for buddy statements, the VA will consider  and give their statements weight.
Buddy statements:
This is an eye witness account, and details help considerably.
The statement  obviously must be from a member of the same unit, same time, place, the veteran was in.
The buddy should give their contact info to the VA-sometimes VA contacts buddys,- and they should sign it with an oath that it is true to the best of their knowledge or get it notarized.
Send Copies to the VA ,and keep the originals.