83d BS(L) constituted November 1940 and activated January 1941. Redesignated 83d BS(M) 30 December 1941. Assigned to 12th BG(M) January 1941 to January 1946. 12th BG(M) assigned to 9th AF in North Africa (two squadrons operated with 12th AF during latter stages of Tunisia Campaign). Attached to 12th AF June to August 1943. Assigned to 12th AF August 1943. Moved to China-Burma-India (CBI) Theater and assigned to 10th AF February 1944. Appears McCars' B-25 went down over Burma.
There may be a deceased file even though no remains were recovered. If so, it'll consist of little more than a death report and paperwork for the memorial stone. Follow the procedure I've suggested. If there's no file, all you've lost is twenty cents and the few minutes it took to prepare the card.