He did serve in France. On page 2 of his record - I am referring to the Service Record on Ancestry - it says he went to France 6 October 1917, and gives details of his medals. Which you only received by serving overseas.
It seems to include pages from two records as the next page is a half burnt version of the previous page, but with clearer writing.
In June 1916 he received a pension of 8s 3d a week for himself and his wife and 6s for his four children. To be reviewed after six months. His health must have got worse as earlier he was assigned to the Z Reserve which was a Reserve that were sent home but had to be prepared to return if fighting started again after November 1918.
He got three days CB (confined to barracks) for not complying with an order of an NCO, while with 683 Company of the LC in Peterborough. There is also mention of a LC Co in North Staffs.
As he medical records are not there it is hard to tell why he was transferred to the Labour Corps.
Added... it seems he served in the North Staffs Regiment before transferring to the Labour Corps. Here is his medal card on Ancestry -
http://tinyurl.com/hmmqsemIt could be the 3rd North Staffs and is the first of the two transfers on his record, with the left hand side missing.
Ken