Stormswift on Family Tree Circles

Hi all, this is a long shot as I have hit a brick wall concerning my maternal Gt Grandfather. I have gathered quite a lot about Charles Bailey, I have his marriage cert, census records for 1901 and 1911. I have also acquired his WW1 service record along with his militia record from 1898/9. Unfortunately with all this I am still unable to a) pin down his birth index. somewhere between 1881-83, b) find his parents name to allow me to delve back further along this line.
I am therefore looking for anyone who may have any knowledge of him or how to go about researching him further.
Charles Bailey:

Marriage Cert -
married Eliza Phillips 24/12/1900 stated age 19, occ Cycle fitter, father William Deceased occ mechanical engineer. Witnesses George & Lena Sadler, don't recognise these as family although not ruled out that it could be a brother or sister.

1911 Census-
Charles & wife to include 5 children. Stated married 10 yrs, age 30 (1881), occ cycle worker, birthplace B'ham.

1901 Census-
Charles with wife and eldest child. Stated married, age 20 (1881), occ Cycle Fitter, birthplace Birmingham.

WW1 Service records. These are damaged by fire but from what I can make out he was born in warwickshire? ( not all there so educated guess)
Now another problem, he has two copies of most papers dated about a week apart. On 12/9/1914 his age is stated as 32 yrs and 213 (218,217) days
18/9/1914 his age is stated as 33 yrs and 2 months?
Both papers occ motor mechanic.
This throws up the possibility of an early 1882 birth.

His Militia record from 1899 doesn't add anything more except a couple of addresses, no next of kin unfortunately. His age is give as 17y2m on his attestation dated 22/8/1899

His children were.
Charles James Phillips
Cissie Bailey married George Beasley
Ada Bailey married George Frederick Green
William Bailey, as yet unsure of who he married
Leonard Bailey married Gladys Turner
Adelaide Bailey married Stanley Sharred

Any thoughts or help appreciated

Steve