So I believe inline LaTeX images are working in gnus, see here
$\sum{\text{ric}}$ and immediately below

$$
\frac{\sum_{n \in \text{daily tasks}}{n}}
{\text{Emacs}} = \text{Org-mode}
$$

This turned out to be fairly easy, and didn't require any encoding or
explicit mime function calls.

I've also re-structured the code so that it should be easy to apply the
appropriate mime markup for WL and VM.  There are now two mime-library
dependent functions `org-mail-file' and `org-mail-multipart' each of
which contains a `case' block for library-specific behavior, e.g.

#+begin_src emacs-lisp
  (case org-mail-mime-library
    ('mml (format (concat "