My private Dr. determined I had Diabetes Mellitus Type II October, 2010. I filed a claim for VA disability benefits in January, 2011 and this claim was denied for failiure to prove I was ever in Vietnam. I served in the Security Service and was TDY to Cam RAn Bay, Vietnam but this command had kept sparse records and my claim was denied. I had also followed up at the VA hospital and was taking Metformin until approximately early 2016. In 2016 I was awarded 10% for diabetes finally proving the NEXUS to service in Vietnam through the help of buddy letters that were not available when my original claim was filed. I was actually told I was SOL because of the nature of my command. Things change and the command is now doing an excellent job of providing buddy letters. I have filed a NOD at the behest of my representative because I believe the VA did not do enough to help me prove I was in country and therefore was exposed to AO. My question is how long will it take for the NOD filed October, 2016 to be addressed; and do you think my argument is sound enough to warrant awarding benefits back to January, 2011? Also since I was on Metformin until 2016 which is documented in the VA hospital records is there a chance that my percentage will be raised from 10% to a higher amount?