mdhihwjv,
I'm sorry that you lost your husband. We can't thank him for his military service but we can still thank you.
I don't understand why vets with MDS and their spouses are sometimes approved for benefits, when many are not. It seems that you have to be extremely persistent and make a strong case with your own medical evidence, such as a statement from a doctor who believes there was a connection. In some cases the benefits get approved, often after years. Whether approval eventually comes or not, the long process seems to leave everyone extremely frustrated.
Whether it's worth all that effort is a personal choice. If you
contact the AA&MDSIF and explain your situation, they may be able to offer you some advice about the process and the chances for success.