Sadly not. you cannot really see what your doing. You could by feel, risk it and try to clean out the old plastic and whatever else with the help of a mirror and torch , but given the hassle ,i would remove the manifolds. the plastic will be well crusted in ,and whatever yo do , dont use a metal object to prise the plastic away. you will dig into the soft alloy and compromise the seal wall. the whole set front and rear manifolds can be removed as one piece , without disturbing the fuel lines and making the job easier. new gaskets are advised upon refitting. if you feel lucky then try your luck in situ , as you are , but as your half way dismantled already i would finish the job making certain all is ok. The inlet manifold gaskets will need renewing if you do decide to do it though. depends on how long you are prepared to wait for gaskets (next day can be arranged for delivery ) .... good luck.
