Maybe I will set up a landing page with some sample letters and submit an HN post...but its nice to think others would have interest outside immediate friends/family.
My father in law is in his eighties and served as a Swedish diplomat in Moscow in the 1960's (among other places). I know he too would love get a chance to read some of those letters.
There are sites that let you set up an email capture box in a few minutes (such as mailchimp). Doesn't have to be a full landing page.