Sorry so late responding, I don't check here very often. I believe you hav to show that you had MS symptoms within 7yrs of getting out, since it can take such a long time to get diagnosed. Do you have a copy of your medical records? If so, go over with a fine tooth comb to check for anything that would suggest symptoms of MS. I was diagnosed after only two years after retiring but there were signs documented about 6-7 years prior to retiring.
Hope this helps!