Your friend apparently doesn't know SU Carbs very well. He may be too young.
The fuel may be coming from the line between the bottom of the float bowl and the jet.
These can be problematic. There is a sort of hard tube going through a rubber washer with
a metal washer to compress the rubber into the threads. It is hard to undo and re-do without
having it leak. (It can be done though - probably need a new rubber washer as they get
hard with use and usually get damaged coming out.
You may be able to find an O-ring that will work.
Do you have the right heat shield between the carbs and the manifold? That will deflect
some of the dripping fuel to a (slightly) less hazardous location.
--
George Downs, Bartlesville, Heart of the USA!