I see you are getting into this "Wallis" thing and noticing the small details. I was going through a bunch of articles and things and in one of them I believe it said that the Wallis Tractor Company didn't sell to the J.I.Case Plow Works until 1919 so it is a bit strange that Malcolm's letter is dated 1916. The one thing I have noticed when reading articles written by people in later time periods is that dates don't always match up with what they truly were. I believe they mean well in writing but things like dates sometimes get mixed up.
If you liked reading that here is a little book I got from a fellow Massey Collector Ron Isdahl here in Minnesota. Maybe after reading this little book of "High Lights" you will be convinced and want to run out and buy a Wallis...