Is your father in law the Roland Ernest Johnson who has an Army Record?
Because if so you are then looking at the address 9 Albion Road in Lewisham.
You could search the electoral registers for some help with this, a Henry Johnson is listed there in 1922 and later, but I haven't looked at them all.
June 1921 Lewisham 1d 944
Johnson Emily C - age 63
Dec 1936 Lewisham 1d 966
Johnson Henry - age 81
There are possible burials on deceased online, I say possible - these are from the free index and Johnson is a common name, but the dates match those death registrations.
24 June 1921 Emily Charlotte Johnson buried at Charlton Cemetery
12 November 1936 Henry Johnson buried at Charlton Cemetery