I am a Jazz music scholar. I had no idea that Bill Evans the pianist was left handed until I read it here in your posting.
He was in the Army Band at Fort Sheridan. I add that because I know it to be true. You did mention he was in the Army Band however you did not say which one.
Fort Sheridan in a little North of Chicago like going to Evanston. It is where I auditioned for the Army Band myself in 1981. I was stationed as a piano player with the 26th Army Band out of Fort Hamilton, Brooklyn, NY. from 1981 to 1983.
I knew Bill had a short life but I did not realize the extent of his addiction to heroin and then cocaine. I learned a lot that I did not know and I know a lot already.
Thanks