1.6.0 with Eclipse 3.1 is 2.5 years old ,)
A couple of things has changed since then.
One of those is that we use Eclipse WTP for the server definitions meaning you need that to be installed and that comes with Eclipse 3.3 EE version.
Oh so is it possible I can activate the internal JBoss icon using Europa RCP?
sorry, but I do not understand your question.