Anything more known about this dear brother?
More of his writings, being extracts from the "Precious Things" magazine, are available on STEM; also a little biographical note - https://www.stempublishing.com/authors/davison/index.html
There are a number of recordings of these two brothers on this website, if you didn't know already, Syd: https://bibleteaching.co.uk/
I also have scans of all of Precious Things, if you are interested; but I'm not the only one who frequents this site who does.