[cairo] modifying, scaling and saving SVG files to PNG using pycairo

[Norman Khine]

Hello,
I have over 400 svg format images which I would like to modify by
merging one image, then resizing this new image to a set size and
finally saving it.
I tried using python to do this but can't get hold of pyrsvg to setup on OS X.
I have built librsvg from mac ports, and now am building gnome-python-desktop

$ port deps gnome-python-desktop
gnome-python-desktop has library dependencies on:
        py25-gtk
        py25-cairo
        gtksourceview
        libgtop
        gnome-media
        gnome-panel
        metacity
        evince
        bug-buddy
        totem-pl-parser

but as always this is taking ages....

Is it possible to do what I want using cairo or is there a different
approach. Basically I would like to create one sprite with some
rollovers so each image will have a different shadow applied to it.

Many thanks

Norman