I'd be recommending a new cu all day long. Fannying about trying to make that old unit compliant will end up being more of a pain than just swapping to a new unit which can be spec'd to suit your current requirements, and for which parts are readily available.
If a jobs worth doing, it's worth doing properly. I'm so glad I packed in doing domestic work.
If a jobs worth doing, it's worth doing properly. I'm so glad I packed in doing domestic work.