I’ll try and pull some pictures w/r to the vacuum controled valves that one should test periodically (particularly if the last test was maybe at the factory)

you have have a nice garage and probably have a lift. Get under and rake a look at your auto transmission line’s flex (rubber) pieces. These are likely wet with trans fluid and this is as big a concern as the old fuel rubber lines. You want to rake care of this ASAP. It’s a matter of removing the lines, taking them a hydraulic
Shop and having them crimp on new lines.

You’ve probably just reattached vacuum hoses to the old fuel pressure regulators and dampeners. Pull the vacuum hoses back off the nipples and use a miti-vac to put vacuum on the nipples, they should hold vacuum. If not, replace the offenders.

That walnut sized vacuum valve attached to your upper cross member (above the engine). Apply mitivac vacuum to it. If it fails to hold, you could end up with vacuum collapsing your fuel tank.

trace the large vacuum hose from the aforementioned vacuum valve back to a plastic vacuum valve (which attaches to your carbon canister). Is there carbon from your (pass fender well) carbon canister sucked up into this plastic vacuum valve? If so, the plastic valve and the carbon canister should be replaced.
To make better since out of all this; pull the vacuum schematics from your shop manual and you can better locate these components. If they are original; they are probably leaking.