By your user name, I assume your grandfather was aboard an LST (smart former MP that I am!).
You may try
United States L.S.T. Association for further information. LST HQ is located in NW Ohio.
My father, Gilbert L. Austing, was assigned to USS LST 818 in the Pacific in the waning days of WW II; I've gained a lot of insight at this website.
Further, there's an LST museum in Evansville, IN (
The USS LST Ship Memorial (USS LST 325)) for LST 325; this LST was purchased from Greece and sailed back to Mobile, AL by a number of former WW II LST sailors-you may wish to consider taking him to Evansville and let him relive his past.
Mike Austing
Dennison, OH