You may be eligible for DIC benefits under the 2019 Blue Water Navy Vietnam Veterans Act.
Will they be able to assist me if I assume his military release date was nearly 65 years ago?
If he was discharged more than 62 years ago, then the National Archives opens all of those records to the public and ordering a copy will be easy.
I'd like to ask another question about VA disability benefits. Is there any other way he could be eligible for disability benefits?