His father couldn't attend the wedding because he died in Calcutta in 1943.
If i remember well, India got its independance in 1947... so Calcutta was still part of the British empire in 1943.
There i need your help, see... In British English, does "M. A. Sassoon late" means the son was called like the father?
It would mean Aubrey junior is the first son...
Or does "M.A." relates to a degree??? (Master of Arts of anything similar?)
It is interesting because an Aubrey Sassoon lived in Lowndes Square in 1952, at number 38!!!!:
Mm. Sassoon (Aubrey junior's mother) was called Rachel. She died in 1964.
She died at age 84 (see middle column)... that means she was born in 1880.
She lived after her husband's death (1943) at the Washington House.
This dates 1954:
The indian connection is reinforced by this document:
It is a passenger list of the ship M.V. Caledonia in 1949 (see last row of the pictured document).
About the occupation of the father... a few possibilities, one of these: here