Given that you have to do all the exact same work to replace the valve, why not just put a brand new compressor in there? It seems like a penny wise / pound foolish decision.

You have to evacuate the system, remove the compressor, clear the lines, clean, etc. It would take more time than just putting a new compressor back in, which at the age/mileage of our cars they probably are due anyway.

But totally your call. Regardless, this is the problem AFAIK.

BTW this is not just me speculating. I had a very similar problem, when through the diagnosis, found that thread and replaced the compressor and everything worked again.