The book itself will include digital images of the actual letters, many of which are on this bizarrely thin onion skin paper.  The letters themselves in some instances contain sketches that get lost in the transcripts as you suggest.  Also included will be digital images of about 50 postcards and modern pictures of many of the items he bought, which he describes in the letters (i.e. Indian bronze table&#x2F;tea kettle, wooding carvings from the Congo, etc...)