/usr/share/doc/emacsen-common/debian-emacs-policy.gz section 8 asks lisp
add-ons to add directories with `debian-pkg-add-load-path-item' rather
than directly modifying `load-path' the way 50a2ps.el does.

I believe debian-pkg-add-load-path-item is available as of "sarge"
emacsen-common 1.4.14 of June 2002.  It aims to keep /usr/local ahead of
packaged lisp dirs so that anything the sysadmin puts in /usr/local has
precedence.

Also in 50a2ps.el it might be better to use the variable
`debian-emacs-flavor' rather than `flavor'.  The latter is only a
let-binding coming from /usr/share/emacs/site-lisp/debian-startup.el,
whereas debian-emacs-flavor is documented in debian-emacs-policy.gz.