Hello John,
Erm ... perhaps copyright problem? - OK for me here in Canada to read, but not you in France?
I got there by Googling this search term (minus the square brackets, but otherwise exactly as I type it here):
["52nd Battalion" "Railway Dug-Outs"]
Naturally Google asked if I didn't mean Dug-Outs without the hyphen, but no, I didn't, because there were hits with both spellings and I searched both.
re Ronald's medal - Yes, I expect it was originally sent to Doris, but this wouldn't necessarily been the first time it was up for sale. Perhaps it was initially sold after Doris' death and four years ago that collector was dead and his estate was being sold? But being as it was only 4 years ago, there may be possibility of contacting the most recent buyer through the auction house and buying that one back again.
re GGBG's - Yes, weekends and holidays reservist force/permanent militia. Remember that this was a time when the map of most of the world was coloured red, "the empire on which the sun never sets", and "The Army" was very much a fact of life and loomed very large in the culture of the day. You'll note that your third soldier had quite a lot of pre-war experience with a C.F.A. (Canadian Field Artillery) unit which may explain his higher wartime rank.
Cheers,
Westoe
