Thanks again everyone.
I wasn't aware of the Probate rule i.e. £5k+ for wills. I'll have a look for his will.
I know that Albert John(jack) Sidwell DAVIS made a number of trips back to Canada, over the years, so I'l take a look for the record that you've found.
Thinking about the issue of Q10 on the Canadian Attestation doc. This must have been a Canadian militia that he belonged to, before signing for the Canadian Expeditionary Forces.
Maurice Brookes