The ever-helpfull and quick-to-search GlosBMD site has the following Records which fit your case;

Birth Details

Child Surname Child Forename Father Surname Mother Surname Mother's Former Name Year District Office Register Entry
DAVIS Russell George DAVIS DAVIS BULLOCK 1890 Gloucester Gloucester, Huntley 18 143

(Bullock is a wellknown Longhope family name)

and

Marriage Details

Groom Surname Groom Forename Bride Surname Bride Forename District Parish Building Year Register Entry
DAVIS Russell George HOOK Emily Ambury Forest of Dean Longhope All Saints 1926 1 380

I wonder if Russell's middle name "George" could possibly be a transcript error, or ???
Interestingly Eliza's middlename is the unusual Ambury, as per this thread's original poster..?

Again searching GlosBMD, for a Davis/Bullock marriage, gives this good fit, the earlier posts show Russell's parents were Jabez & Sarah Davies;

Groom Surname Groom Forename Bride Surname Bride Forename District Parish Building Year Register Entry
DAVIS Jabez BULLOCK Sarah Jane Forest of Dean Westbury-on-Severn (FoD) Register Office 1884 7 152

http://ww3.gloucestershire.gov.uk/bmd/MarriageSearch.aspx

Clearly needs more work but looking good for you Dan !

As expected FreeBMD backs these up;

Births Dec 1890 (>99%)
--------------------------------------------------------------------------------
Davis Russell George Westbury S. 6a 229

Surname First name(s) Spouse District Vol Page
--------------------------------------------------------------------------------
Marriages Mar 1926 (>99%)
--------------------------------------------------------------------------------
Davis Russell G Hook Westbury S 6a 355
Hook Emily A Davis Westbury S. 6a 355

This FoD site's PRs include the above marriage which is very helpfull;

Record_ID: 1007052
Entry_Number: 380
Year: 1926
Month: Feb
Day: 13
Grooms_Surname: DAVIS
Grooms_Forenames: Russell George
Grooms_Age: 35
Groom_Condition: Batchelor
Grooms_Occupation: Builder
Grooms_Residence: Brookside Longhope
Grooms_Fathers_Surname: Davis
Grooms_Fathers_Forenames: Jabez
Grooms_Fathers_Occupation: Builder
Brides_Surname: HOOK
Brides_Forenames: Emily Ambury
Brides_Age: 33
Brides_Condition: Spinster
Brides_Occupation: [not stated]
Brides_Residence: Upper End Longhope
Brides_Fathers_Surname: Hook
Brides_Fathers_Forenames: William
Brides_Fathers_Occupation: Woodworker
Licence_or_Banns: [not stated]
Date_of_Banns:
Signature_or_Mark: Both Sign
Witness_1: M Carter
Witness_2: G Hook
Other_Witnesses:
Officiating_Minister: Edward M T Marsden Rector
Event: Marriage
Memoranda:
Notes:
Register_Reference: P206 IN 1/7
Page_Number: 190
Parish_Chapel: Longhope
Soundex_Groom: D120
Soundex_Bride: H200

Record_ID: 136351
Entry_Number: 1027
Year: 1893
Month: Oct
Day: 1
Parents_Surname: HOOK
Child_Forenames: Emily Ambury
Fathers_Forenames: William
Mothers_Forenames: Jane
Mothers_Surname:
Residence: Longhope
Occupation: Hoop Maker
Officiating_Minister: E.B.Shekell Curate
Event: Baptism
Memoranda:
Notes:
Register_Reference:
Page_Number: 129
Parish_Chapel: Longhope
Soundex: H200

Record_ID: 136552
Entry_Number: 1230
Year: 1912
Month: Feb
Day: 25
Parents_Surname: DAVIS
Child_Forenames: Russell George
Fathers_Forenames: Jabez
Mothers_Forenames: Sarah
Mothers_Surname:
Residence: Pittstowe House Little London Longhope
Occupation: Builder
Officiating_Minister: George Barr M A Rector
Event: Baptism
Memoranda: Born 3 Oct 1890
Notes:
Register_Reference:
Page_Number: 154
Parish_Chapel: Longhope
Soundex: D120

==============================

Dan,
I see Ambury's name is still displayed as blue, hence "active", altho clicking on it suggests they've not visited the forum since 2012. I suggest you mail Ambury direct bu clicking their username, they'll hopefully get your email and may be able to help clarify things further.
Have you seen the excellent Longhope Village website ?. I see it contains photos of Jabez and Sarah's grave, both lived long lives 'til about age 90, and hopefully the site will provide much more of interest to you.
http://www.longhopevillage.co.uk/FamilyHistory/AllSaints/Search.aspx
Hoping this helps, Jeff.

Any help would be greatly appreciated

Dan

1891 Hope Hill
Jabez Davis abt 1862 , Gloucester; Longhope Head Longhope, Gloucestershire Mason
Sarah Davis abt 1865 , Gloucester; Longhope Wife Longhope, Gloucestershire
Ali[CE] Ruth Davis abt 1884 , Gloucester; Longhope Daughter Longhope, Gloucestershire
Annie Davis abt 1887 , Gloucester; Longhope Daughter Longhope, Gloucestershire
Russell Davis abt 1890 , Gloucester; Longhope Son Longhope, Gloucestershire

1901
Jabez Davis abt 1863 N Head Worcester, Worcestershire
Sarah Davis abt 1865 Gloucestershire, England Wife Worcester, Worcestershire
Russell Davis abt 1891 Longhope, Gloucestershire, England Son Worcester, Worcestershire
Eva Davis abt 1893 Longhope, Gloucestershire, England Daughter Worcester, Worcestershire
Elsie Davis abt 1895 Longhope, Gloucestershire, England Daughter Worcester, Worcestershire
Walter Davis abt 1897 Longhope, Gloucestershire, England Son Worcester, Worcestershire
Emily Davis abt 1900 Longhope, Gloucestershire, England Daughter Worcester, Worcestershire

1901
Alice R Davis abt 1883 Longhope, Gloucestershire, England Servant Worcester, Worcestershire

1911
DAVIS JABEZ M 1863 48 Westbury on Severn Gloucestershire
DAVIS SARAH F 1866 45 Westbury on Severn Gloucestershire
DAVIS ANNIE F 1887 24 Westbury on Severn Gloucestershire
DAVIS EMILY F 1900 11 Westbury on Severn Gloucestershire
DAVIS RUSSELL M 1891 20 Westbury on Severn Gloucestershire
DAVIS WALTER M 1897 14 Westbury on Severn Gloucestershire
DAVIS HAROLD M 1911 3 MONTHS Westbury on Severn Gloucestershire