It's amazing what you can find on the web

For instance, a photograph of a 1966 letter from J. R. R. Tolkien to Don Wollheim.

February 10th, 1966
Dear Mr. Wollheim,

I regret the delay in replying to your letter of Jan 27th. I have been away from home - I was am an advance victim of the influenza epidemic now widespread in this country. Thanks for your expressions of esteem,

Yours Sincerely
J.R.R. Tolkien

Enclosed: two copies of the proposed agreement, signed. Also a copy of an 'agreed statement' which I will send out as soon as I hear that it is acceptable.

JRRT