When the Selective Service Act was passed in 1940 the Continental U. S. was divided into nine regions. Accordingly, the army began issuing eight-digit service numbers. The first digit revealed the individual's component - Regular Army, National Guard or Enlisted Reserve Corps (inductee). The second digit represented the geographical region in which the individual entered service.
This wouldn't be an effective means for tracing an individual. For example, the service number 38 245 881 indicates only that the individual was inducted (drafted) somewhere in Arkansas, New Mexico, Oklahoma or Texas. He could have been a native of New York, South Dakota, California or just about anywhere in the world.
I'd ask you to send me your list but I'm not taking on any more in-depth research right now. Check with me in a couple months or so.