Hello Jean,
Your luck may be changing

I finally found this entry after starting at 1918
Deaths Q3 (Sept) 1952 Deptford 5c 320
BARR Ernest M age 70If you can't access it yourself, PM me.
He may have taken a trip down Creek Road and forgotten to tell anyone.
I imagine he would have been demobbed at a Dispersal Unit back in England, whether at his point of entry or possibly Woolwich, I don't know.
Am I right in thinking that he did not marry? I couldn't find anything on FreeBMD.
It looks like your next move is the Local History room at Lewisham Library. They have a fairly good selection of directories and electoral rolls there and I think they can access the rolls that aren't on site. My wife found out about the original owner of our house (lived here 1901 to 1953), when we moved up here. John Coulter, who runs it, was very helpful.
Phil