The 320th Glider Field Artillery Battalion was later redesignated 320th Field Artillery, a parent regiment under the Combat Arms Regimental System (CARS). You may be able to secure unit history information from the division veterans association. They may also assist in locating someone who served with him. Their address is:
82nd Airborne Division Association Post Office Box 9308 Fayetteville, North Carolina28311-9308 (910)822-4534 < ABN82DASSN@aol.com >
You may also want to inquire whether there is a 320th Artillery regimental veterans association.