*** - invalid byte #x81 in CHARSET:ISO-8859-1 conversion
1. Break NEWS[2]> where

EVAL frame for form (READ-LINE INS NIL 'EOF)

By looking at a backtrace, I can see that what it's "freaking at" is
that it's reading a line with a name that contains a "funny
international accent," which presumably isn't fitting well into
ISO-8859-1.

Relevant code fragment:
(with-open-file (inp-stream input-file)
                (format outs "From: cbbro...@hex.net~%")
                (format outs "Reply-to: cbbro...@hex.net~%")
                (do ((line (read-line inp-stream)
                           (read-line inp-stream nil 'eof)))
                            ((eq line 'eof) "Reached end of file.")
                      (rewrite-line line outs)))

Now, I had been _thinking_ that all this readtable stuff that has been
causing such bluster was pretty irrelevant to me, and that I could,
for the time being, just ignore it from a practical perspective.  

  Windows' apostrophes are usually taken from the typographic are of
  Unicode and mapped into high control area (0x80-0x9F) just to screw
  with people who like the ISO 8859-1 standard.

| Now, I had been _thinking_ that all this readtable stuff that has been
| causing such bluster was pretty irrelevant to me, and that I could,
| for the time being, just ignore it from a practical perspective.  

  It has nothing to do with readtables, ut everything to do with
  external-format processing.

| It now seems otherwise; it seems as if I need to attach some sort of
| readtable information _somewhere_; I'm not quite clear on where.

  See your system documentation on the available and default external-
  format settings to open (and friends).