Westbury on Severn is where I would start looking

Name: John Barnes
Name: Phoebe Marshall
Year of Registration: 1839
Quarter of Registration: Oct-Nov-Dec
District: Westbury On Severn
County: Gloucestershire
Volume: 11
Page: 657

Year: 1839
Month: Nov
Day: 14

Groom Surname: BARNES
Groom Forenames: John
Groom Age at Marriage: Full Age
Groom condition: Widower
Groom Rank or Profession: Labourer
Groom Residence: Hundred of St Briavels
Groom Father's Surname: Barnes
Groom Father's Forenames: James
Groom Father's Rank or Profession: Hawker

Bride Surname: MARSHALL
Bride Forenames: Phoebe
Bride Age at Marriage: Full Age
Bride Condition: Spinster
Bride Rank or Profession:
Bride Residence: Hundred of St Briavels
Bride Father's Surname: Marshall
Bride Father's Forenames: John
Bride Father's Rank or Profession: Mason

Licence or Banns: Banns
Date of banns:
Signature or Mark: Both mark
Witness 1: Mark of James Roberts
Witness 2: Sarah Roberts
Other witnesses:
Officiating Minister: William Crawley
Event type: Marriage
Memoranda:
Transcriber's Notes:
Register Reference: P145 IN 1/11
Page No: 15
Parish_Chapel: Flaxley