My grand father had four bothers, unfortunately two of them died within twelve months of birth, one died age ten and the youngest wasn't born until 1931. He also had four sisters, one married in 1935 two of them married in 1945 and the youngest never married.
My great grandfather was born 1888-1889 according to his military records and 1939 reg. He died in military of pensions hospital in Leeds in 1942. So if this wedding is dated after 1945 in cannot be him.
Unfortunately i haven't been able to find any details on my great grandfather before he joined the army in 1910, so i do not know if he had any brothers.