Helpful suggestion ladyhawk but no I don’t have exact date of birth unfortunately as it might help eliminate or confirm the death in 1954.
Have you found all his family in 1921?
Ernest John Sorrell
Enlistment Age 23
Birth Place Great Watham, Essex
Regimental Number 39
Regiment Name Head Qts Coy
Number of Images 14
Form Title Attestation
Damaged but can make out
father John Sorrell, Howe Street, Gt Wal
As you probably aware instant digital images are available on GRO but I couldn’t find a matching entry
for this birth showing mmn

Arthur George Sorrell 1881 Jan-Feb-Mar Chelmsford, Essex Volume 4a Page 318
Did he marry?