DoB from obituary where he was described as 30 in 1945.

Record Type Parish Baptism
Date of Birth 17 Nov 1919
Name Mary Boyd Gray
Gender F
Fathers Name William John Gray
Mothers Maiden Name Jeanie 
Date of Baptism 19 Dec 1920
Church Garvagh First Presbyterian Church
Civil District  Coleraine
County Londonderry

Civil Birth Record
Name:    Mary Boyd Gray    Date of Birth:    17-Nov-1919
         Registration Date:    
Address:    Garvagh    Parish/District:    GARVAGH
Gender:    Female    County    Co. Derry
Denomination:    Registrar District
Father:    William Gray    Mother:    Janie Mcclements
Occupation:    Mason        
Sponsor 1 /
Informant 1:    Janie Gray
Sponsor 2 /
Informant 2:    
Notes:
This record comes from "Garvagh Registration District" according to RootsIreland.  And yet, it is NOT at GRONI!