Hi, I have been looking in to the Battle of Selle as my Great-Gran's uncle died there on the 17th October. He was serving with the Fourth Army, however, I have found some information that, might, be of interest to you. There is a diary from a man called Capt. Arthur Impey, he was with the V Corp of the Third Army (where I believe the person you are researching was):
http://www.hellfirecorner.co.uk/tucker/tuckercontext.htm Here, there is a specific reference to the 113th Division on about the 8th October “During that day’s attack Impey had noted that ‘our friends the Welshmen seemed to be holding up the right flank as usual’. This was a reference to the 38th Welsh Division, specifically 113 and 115 Brigades.”
I hope I'm right in saying that the Royal Welsh Fusiliers 13th Battalion, part of the 113th Brigade, were in the 38th Division of the V Corp in the Third Army. They were fighting North of the town name Le Cateau (now renamed Le Cateau-Cambrésis). A book, by General Archibald Montgomery, was written about the last 100 days of the war for the Fourth Army, the V Corp is mentioned a few of times as they fought very close together. Here's the link to the online book, it can be downloaded in a PDF file:
https://archive.org/details/storyoffourtharm00montAlong with this book, there was set of maps occupying it, the one you will probably find best is this one:
http://www.nla.gov.au/apps/cdview/?pi=nla.map-vn100316-s15-sd&rgn=0.0947164948,0.0021905805,0.8679123711,0.6593647317&width=1200&cmd=zoomoutIf you want to see other maps from the book, where it says: “Search > Item > Interactive Map Part 15” Click "Item" and you will be able to select any of the other maps from the series.
I hope that this information is of use to you,
Emfranky.