RFC: initial syweb port

I made an initial port for syweb (a php frontend to symon) and have a
question. The port consists of a set of files under /var/www and 1 utility
script. The script helps ppl install rrdtool inside the apache chroot.

I'd like to install the script in /usr/local/share/syweb/install_rrdtool.sh. I
managed to do this, but get the impression "that things are not supposed to
work like this".

Offending snippets follow:

-- Makefile --
PREFIX=                 /var/www
CMDPREFIX=              /usr/local/share/syweb

do-install:
        ${TAR} -C ${WRKDIR}/syweb -cpf - htdocs symon | \
                ${TAR} -C ${PREFIX} -xpf -
        mkdir -p ${PREFIX}/../..${CMDPREFIX}
        cp ${WRKDIR}/syweb/install_rrdtool.sh ${PREFIX}/../..${CMDPREFIX}
-- PLIST --
htdocs/syweb/symon.png
htdocs/syweb/tools.inc
symon/pf.layout
@exec mkdir -p %D/symon/cache
@exec chown www.www %D/symon/cache
@exec mkdir -p %D/symon/rrds
@cwd /usr/local/share/syweb
install_rrdtool.sh
--

How would you guys solve this?

Cheers,
Willem
Ps. Entire port tar at
http://www.xs4all.nl/~wpd/symon/philes/ports-syweb-0.4.tar.gz.