Letters from Father Christmas is indeed a delight! It must have been such a joy for the children to get these letters. Evidently Tolkien sometimes "found" the letters by the chimney, their envelopes still dusted with snow (he drew stamps too!), and in later years enlisted the postman to deliver them.

David Copperfield is looking like it will be a long term project, so there may be many posts to refresh your memory! I just got to the bit where David's widowed mother marries the horrible Murdstone.