I have spent about 60-70 hours at my computer seeking information on the 307th Service Battalion, QMC. So far I have located references to 8 men who belonged to this Battalion. All were black men and of the five draft cards I have located, all were illiterate. In the Google book "Scott's official History of the American Negro in the World War", pages 316-317, Scott lists the Negronon-combatant organizations that served overseas. The list includes Labor Battalions 304-315, 317-327, 329-348 and 357. There is no reference to Service Battalions.
To quote Homer Simpson, "Duh" .. of course in 1918 they were called the "Service of Supply" and became... Service Battalions. So they were drafted into Labor Battalions and were discharged as Service Battalion and that's what is carved into their tombstones. Does anyone disagree? Can I say this in front of 100 people at a family reunion?