Soldiers Died In Great War will give a mix of Born,Enlisted and Residence its available on ancestry
For Thomas it gives Born Govan,Residence Dumbarton Enlisted Glasgow
For living casualties its much harder if records were destroyed in ww2 as 70% were.You have to basically find any records that survive to similar numbered men of the same regiments and see what the records say....
The Medal Rolls at Kew will give the date of enlistment
Lads that enlisted before 1916 were all volunteers as conscription came in in 1916.
Ady