Where are you? I have several spares (Sacramento, CA). If pressed, you could custom plumb. Post 9 shows some parts. I recall seeing generic vac booster check valves in bubble packs at Autozone. Most are for the type which push into a rubber grommet on the booster, but might be some inline hose type. Also search on ebay and Amazon.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans