Do you have the text of the letter he sent to the German publisher asking if he was "Aryan"?
I thought I had saved it, but can't find it on my hard drive, and since "The Hobbit Hole" threads are something like 100,000 posts each I wouldn't know where to start to look.
Here is an excerpt of it:
25 July 1938
Dear Sirs,
[...]if I am to understand that you are enquiring whether I am of Jewish origin, I can only reply that I appear to have no ancestors of that gifted people. My great-great-grandfather came to England in the eighteenth century from Germany[...] I have been accustomed, nonetheless, to regard my German name with pride, and continued to do so throughout the period of the late regrettable war, in which I served in the English army. I cannot, however, forbear to comment that if impertinent and irrelevant inquiries of this sort are to become the rule in matters of literature, then the time is not far distant when a German name will no longer be a matter of pride.
[...]
J.R.R. Tolkien
The Letters of J.R.R. Tolkien, pp. 37-38