[Mithalwen]

I would think it quite likely that there are many letter out there given that Tolkien was a child of the letter writing age - yes there was a time when the post was a reliable and swift form of communication! Many people do routinely keep letters and many more would keep one from someone of significance. Of course it doesn't follow that many of these letters would have any great significance but I am sure many people would like such a personal thing as a handwritten letter even if it were querying a gas bill!