The carby you just purchased, looks to me.................not to be an aussie delivered model (maybe off an import 5k or something), Now the hose you have labelled number "2", Where exactly does the other end run to? Under Where your fuel feed bolts into the top hat of the carby..........................is the an outlet for a vacuum hose underneath it? Outlet "1" looks like to be a bowl breather, Outlet "3" and "4" are constand vacuum lines, these are the two causing your car to run "rough" as to causing a vacuum leak. Outlet number "5", i need a better pic as to where exactly on the carby is positioned as to determine What its likely purpose is. By looking in the pictures you have provided, your running a late ke55, ke70 exhaust/inlet manifolds. If possible, could you provide more pics of the overall hoses associated with the carby?