There are two Angela Riley births in England and Wales in the period 1945 (38 at marriage) to 1965 (18 at marriage) but both have a second initial.  I think her marriage certificate is needed to identify her birth.   It would also give Roger’s age at marriage and thus his approximate birth year.

(Sounds like I am going for legal Powys descendants.)
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From their marriage certificate she was 20 at marriage so born from 22nd May 1962 to 21st May 1963.

In 1962/3 there are these births of ‘Angela Riley’, no middle initial, on FindMyPast’s index in 1962 and 1963:

Last name  First name(s)  Year Of Birth  Location
Riley      Angela         1962           Durham Eastern, Durham
Riley      Angela         1962           Ormskirk, Lancashire
Riley      Angela         1962           Middlesbrough, Yorkshire
Riley      Angela         1962           Pontefract, Yorkshire
Riley      Angela         1963           Barton, Lancashire
Riley      Angela         1963           Barnsley, Yorkshire
Riley      Angela         1963           Hemsworth, Yorkshire

Her father was Arthur Cedric Riley.  He would have been around in 1939.  Where was he living then?
And when did he marry?

We might just get hold of her mother’s name too.  Might she have been the Elaine Riley who signed her marriage certificate?  As likely Elaine might have been her sister.
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there was a marriage of Arthur C Riley to Norma A Price in 1962 in Barton … and …
There was a birth of an Elaine Riley with a Price mother in 1965 in Barton, Lancs  … and  …
An Angela Riley was born in Barton in 1963  …  and her mother’s name was Price.

So it might be worth getting a birth certificate for the last to see if the father was Arthur Cedric:

First name(s)         Angela
Last name             Riley
Birth quarter         1
Birth year            1963
Mother's maiden name  Price
District              Barton
County                Lancashire
Country               England
Volume                10B
Page                  353
Record set            England & Wales Births 1837-2006

The only problem with the above is that she was married in Urmston, Lancs and resident there at that time in 1983.  Her parents could have moved from Barton, of course.

Leave it for 24 hours to see if I still think it is worth a tenner.  Ordered on 8th Feb 2022.
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The birth certificate arrive around 16th Feb 2022 (not bad).  Deatils:

Registration district:  Barton
Year:                   1963
Sub-district:           Stretford
County of:              Lancaster

Reg No:                 421
Date of birth:          Third January 1963
Whwere:                 Stretford M emorial Hospital, Old Trafford
Name:                   Angela
Sex:                    Girl
Father:                 Arthur Cedric Riley
Mother:                 Norma Ann Riley formerly Price, of 2 Lindum Avenue, Stretford
Father’s job:           Lithographic Printer
Informant:              Norma Ann Riley, mother, 2 Lindum Avenue Manchester 1§6
Reg date:               Twenty eighth January 1963
Registrar:              (can’t work out the name!)

All corresponds to my best guesses.)

Their marriage index:

First name(s)       Roger A
Last name           Dickin
Marriage quarter    2
Marriage year       1983
Marriage Finder     Roger A Dickin married one of these people
                    Angela Riley
Spouse's last name  Riley
District            Trafford
County              Lancashire
Country             England
Volume              39
Page number         1572
Record set          England & Wales Marriages 1837-2005
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Their marriage certificate has arrived on 3rd February 2022:

“1983 Marriage solemnized at St Clement’s Parish Church in the Parish of
“Urmston in the Metropolitan District of Trafford

“No:            38
“When married:  21st May 1983

                   His                                 Hers
                   ===                                 ====
“Name:          Roger Anthony Dickin                Angela Riley
“Age:           24                                  20
“Condition:     Bachelor                            Spinster
“Profession:    Bank Clerk                          Nurse
“Residence:     304 Moorside Road, Davyhulme        3 Newcroft Road, Urmston
“Father:        Thomas Lloyd Robert Spencer Dickin  Arthur Cedric Riley
“Father’s job:  Chartered Engineer                  Managing Director

“Married in the Parish Church according to the rites and ceremonies of
“  this Church of England after Banns by me, B Dunwoody, Vicar

“This marriage was solemnized between us,  Roger A Dickin, Angela Riley
“  in the presence of us,  Gary Kirk, Elaine Rigby
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