I am not sure if this will help you, but I am researching my grandfather who served in WWI.As best as I can tell he served in Co. A 82nd - 307 Ammu.This was written in his cap, which I still have.It states that he was in Grievres, France on March 12, 1918.I've googled the 307 and found some information, but not much.
In one obituary I found for a gentleman from Alabama it states:
SCHMITTOU, Rudolph S., serial number 1,919,883W, 1st Corporal, Co. B, 307th Amm. Tr., was born 24 December 1892 at Louise, Montgomery County, TN. He died 11 May 1967 at Topsy, Wayne Co., TN and is buried in the Durham Cemetery. He enlisted on 13 November 1917 at Allens Creek, Wayne Co., TN as a private. He was honorably discharged on 24 May 1919 at Ft. Oglethorpe, GA and given $89.22 for travel expenses home. He was a farmer and a railroad fireman...During the war he served in the Marbache Sector, St. Miehel Sector and the Meuse Argonne Offensive from 25 June to 9 Nov 1918. He hauled ammunition to the front lines. "
I have since uncovered a notebook of his that lists his movements - but I have not transcribed it as of yet.
Have you looked at the US Archives?They keep military records there.
I will keep your relatives info in my file in case I come across his name.