I have same problem. After doing some spins with an instructor this summer I got a fuel stain in my new headliner.
The couplings look to be old and I see blue staining there. The worm clamps look to be in terrible shape too. Hopefully it's just this and not the whole line has corroded thru so the headliner won't have to come down.
'66-G model, O-300 145 HP Conti, "Smooth Sixie"