This is rather cool. It seems like the research into older system line drawing symbols (towards the bottom of the document) and which fills the PUA section of the font might make a good basis for a Unicode proposal to add some of them.
Q: What are private-use characters?
A: Private-use characters are code points whose interpretation is not specified by a character encoding standard and whose use and interpretation may be determined by private agreement among cooperating users. Private-use characters are sometimes also referred to as user-defined characters (UDC) or vendor-defined characters (VDC).