Starting from emacs24 -q,

    M-x load-library elscreen
    C-h f elscreen-create

doesn't have a link button to the elscreen.el source code, where I
hoped it would.

In emacs24, the .el must be in the same directory as the .elc to be
recognised as its source code.  Recent emacsen policy
/usr/share/doc/emacsen-common/debian-emacs-policy.gz section 5 part E
asks packages to symlink the .el files to the flavour directory for that
purpose.

So /usr/lib/emacsen-common/packages/install/elscreen would "ln -s"
instead of cp, and rm path.el only, leaving the .el source symlinks for
the help system, to be removed later by
/usr/lib/emacsen-common/packages/remove/elscreen.

Incidentally I see /usr/lib/emacsen-common/packages/install/elscreen has
a copy of the install-info-altdir block.  But elscreen doesn't have a
.info file for that to act on does it? .. if install-info-altdir ever
does one day exist.