My father, still on the hunt for militaria, came across the 2nd Batallion Discs at a car boot sale in the UK for 2 pounds, he didn't have his glasses at the time so when he got back to the car he was surprised to see they were Canadian.
Credit to Library and Archives Canada for making the service files available I was able to find his records
https://www.bac-lac.gc.ca/eng/discover/military-heritage/first-world-war/personnel-records/Pages/item.aspx?IdNumber=482517
the single I found at an antique mall in Southern Ontario, labeled as a "tool tag" but of course its not, I had a bit of trouble initially searching for this fellow, however I soon realized it was Clark not Clarke !
I found his details here
https://www.bac-lac.gc.ca/eng/discover/military-heritage/first-world-war/personnel-records/Pages/item.aspx?IdNumber=102929
Interestingly but not unusual, both were born in the UK
Hopefully if you are searching service no's, ID tags you will find the LAC Site Useful