I have been able to remake/rebuild the check and relief valves that screw into the intake manifold. This setup is not like original but does work just like the original. I am going to offer them in two different setups. One will be with an aftermarket custom relief valve screwed into the top of the original valve with a custom cap. The other option will be the original valve with the original cap that is modified so that you can install the custom relief valve into the line going to the depressurization valve. This setup will come with the T fitting allowing you to cut the depressurization hose and install. This method will hide the valve a little more than the one screwed into the cap. I like this option a little better for other reasons as well but will not get into the boring details of that. I have had one on our automatic car for 400 miles and still going strong. I just sold the last one I had ready but have more in the works. I should have 4 ready to send to Jim to have crimped soon. I will have two of each style done.
Another member here is working on reproducing the original diaphragm so that it can be set up like Oldsmobile did it back in the day. I am not sure where he is on the project but maybe he will have his available soon also.
I will have $150 each on the ones that mount in the cap and $125 each for the ones that mount in the hose with the T fitting. This will also require a core in return so I can have something to rebuild for the next guy. The core must not be bent on the upper flange or severely rusted but a little surface rust is ok. The price may sound high but I have several hands in it. There is the custom made valve, a guy machining the cap for the top style and Jim crimping them together and shipping to and back from Jim. all this adds up. Jim did not charge me for the first ones but now that we have them lined out I have to cover his time also.