IFSM Leaking

[Chamberpains]

That leaking actuator looks like a gasket failure. Did you replace the gasket when it was replaced and did you torque the cap screws down properly? Cummin quickserve will have the proper installation and torque spec. I believe its only inch\lbs its gets torqued to. Also the wires going to the actuator look like they've been repaired or are swollen from fuel saturation. You may want to take a hard look at the whole harness and replace it if necessary. They are a common failure point the older they get.
The fuel pump looks to be factory and never replaced. It looks like its leaking so I would be looking to replace it. But you can clean it up and run it to see if the leak comes back. Also quickserve should have guidelines on when to replace that pump.
When was the last time you had the overhead ran on that truck?

What kind of operations has this truck been used for? 485,000 miles is really low for how old it is. I'd want to be sure its legit mileage reading. Just for fear of not knowing things are older and more worn.