Update: I loosened the fuel inlet to the fuel cooler, driver’s side of the engine compartment. It wasn’t dry; about a tablespoon of clean fuel dripped out but it wasn’t under pressure. I connected clear vinyl tubing here and directed it to a container. When I turned the key on I could hear the pumps come on and run about 1 second then stop. No fuel came out of the connection.
Next I plan to loosen what I have identified is the other end of this fuel
Line, and blow through it with compressed air.
I also see a device just ahead and above the fuel filter (new filter, by the way); a device which looks like it could have a diaphragm: maybe a fuel pressure regulator?

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Providing a home for these cars:
1951 Buick Special De Luxe
1977 Rolls-Royce Silver Wraith II
1970 Rolls-Royce Silver Shadow
1986 Mercedes-Benz 420 SEL
2005 Mercedes-Benz E 320 CDI
2012 GMC Sierra 1500 4X4
1927 Pierce-Arrow Series 80
1931 Pierce-Arrow Series 43
1926 Ford Model T coupe