I located a brief reference to your 599th. AAA Automatic Weapons Battalion, in "World War II Order of Battle", by Shelby L. Stanton.
The unit left NYPE 10Dec44, arrived England 16Dec44,arvd. France 5Mar45.
It did not participate in the D-Day Invasion of Normandy, nor was it a participant of the Ardannes-Alsace campaign.
It did win citations for (26) Central Europe, 22Mar45-11May45, and (34) Rhineland, 15Sep44- 21Mar45 campaigns.
It was located at Eining, Germany 15Aug45 at the end of the war.
It arrived at Hampton Roads, VA P/E 7Dec45.
I checked a second reference and located a Sgt. Bill Slape of the I&R Platoon, 394th. Regiment, 99th Infantry Division mentioned. He was at the Battle of the Bulge 12/19Dec44. I thought that he may be related since that is not too common a name.
This reference is from "Citizen Soldiers" by Stephen E. Ambrose.