His birth index:

First name(s)         Adrian D
Last name             Henderson
Birth quarter         4
Birth year            1922
Mother's maiden name  Maclean
District              Chertsey
County                Surrey
Country               England
Volume                2A
Page                  112
Record set            England & Wales Births 1837-2006
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In 1939 he was at Eton College Manor House, Eton, Buckinghamshire:

First name(s)  Last name(s)  DOB          Sex   Occupation  Marital status  Schedule  Schedule Sub Number
Adrian D       Henderson     29 Sep 1922  Male  At School   Single          11        17
Ref: RG101/2112H/011/43
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For his first marriage 15 Henderson births can be found between 1944 and 1964 with mother’s maiden names of Webster.  They divorced in 1958 which brings the number down to 11.  Of these 11 one is their second son.  The registration of their first son’s birth cannot be found on FindMyPast, or FreeBMD or Ancestry; might it have been abroad?  Abroad does not make sny sense in wartime, not when the marriage was just over nine months before the birth.  One possibility is that this Adrian was abroad at the time of his son Gavin’s birth and somehow his wife failed to register the birth; it may have got registered many years later when the omission was realised; what happens then?
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His death index:

First name(s)               Adrian Donald
Last name                   Henderson
Gender                      Male
Birth day                   29
Birth month                 11
Birth year                  1922
Death quarter               1
Death year                  1994
District                    Salisbury
District number             7951A
Register number             A36C
Entry number                132
Date of registration mm/yy  0194
County                      Wiltshire
Country                     England
Record set                  England & Wales Deaths 1837-2007
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This causes a bit of interest.  In 1939 someone at Eton entered that he had been born on 29 Septmber 1922.  But after he died a close contact told the registrar that he was born on 29 November 1922.  Which was right?  The only answer is to get his actual birth certificate, but that is not needed for any more serious reason, so I shall leave it be as it is.
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His probate index:

1994
HENDERSON, Adrian Donald
of The Manor Cottage Kilmington Warminster died 02 January 1994  Probate Winchester 13 April
£151682    9452409411V
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Their marriage index:

First name(s)       Adrian D
Last name           Henderson
Marriage quarter    1
Marriage year       1944
MarriageFinder      Adrian D Henderson married one of these people
                    Marie D Webster
Spouse's last name  Webster
District            Marylebone
County              London
Country             England
Volume              1A
Page number         1051
Record set          England & Wales Marriages 1837-2005
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Their marriage index:

First name(s)       Adrian D
Last name           Henderson
Marriage quarter    1
Marriage year       1959
MarriageFinder      Adrian D Henderson married one of these people
                    Angela M Pollen
Spouse's last name  Pollen
District            Kensington
County              London
Country             England
Volume              5C
Page number         2710
Record set          England & Wales Marriages 1837-2005
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