24 Sussex Street
5 Oct. 
We are ready to receive you and the Queen!
The following is a summary of things:
1. You have a morning suit "in toto"--my trousers are 38" at waist.
2. You will bring your tuxedo shirt, studs, etc.
3. You will be seated in the Governor General's box which will also have a seat vacant for Mother. It's too bad she can't travel as she would have been the "Belle of the Ball"--the only mother who ever saw her son as a Prime Minister.
4. You will be at the dinner [for] H. M. [Her Majesty] at our place and I'll try to get you in on a reception too.
I suppose this will be a tough session of Parliament. Anyway, we will try to do our best.
Monday I speak to McGill and hope that I can think of something to say--day after tomorrow, whew!--and not one line of a speech as yet.
All the best and will see you soon.
-from Personal Letters of a Public Man: The Family Letters of John G. Diefenbaker edited by Thad McIlroy; with an Introduction by J. L. Granatstein (Toronto: Doubleday Canada, 1985) p.80-81.