I haven't gotten the new breather elbows yet, and I will post an update as soon as I replace them, but I happened to have had the necessity of taking a few pictures of the engine during the past couple of days (for an unreleted reason), so I thought, for the sake of completeness, to take also one of the valve cover to post here.
Compare the new picture to the first one posted in this thread in 2005... The current picture shows that there is absolutely no oil around the filler cap, and just a bit of oil coming out of the breather elbow, which then flows down on the left side of the cover (not visible in the photo). The last time I cleaned the valve cover was two years ago right after installing the screw clamps...

You can also see all the filth covering most of the engine... due to the smoke caused by the leaking oil getting in contact with the hot engine and being burnt back then... BTW, how do I clean the engine (kerosene, commercial products, steam?) I have been post-poning the cleaning all along because someone warned that engine components could be harmed if the cleaning is done incompetently... and so I have been afraid of making a mistake and screwing up something in the process...

Attachment 42287

Rino

You could also check the tube that is attached to the elbow. It could have a small crack or could have been deformed due to overtightening. Mine used to be plastic. I have since replaced it with a stainless tube so that I could tighten it more with the clamp. It is still leaking a bit but not as bad as before.

As I pointed out earlier in this thread, the leak is taking place at the connection between rubber and metal (lower part of the breather hose and valve cover intake)... The part where the breather elbow attaches with the hose is totally dry.
Thanks anyway, though.

Rino

Update...
 

OK, the new breather hoses haven't gotten here yet, but something significant has taken place. I did an Italian tune-up yesterday (25 miles) and one today (50 miles), really pushing the car to the limit. This is the first time I do something like that since buying the car two years ago. Before the first one, yesterday, I cleaned the area on the cover around the breather hose. Well, there hasn't been a single drop of oil leaking out of that juncture since, in spite of all that hard driving...

So, if the leak were occurring because of a damaged/worn-out elbow, it would make sense that more leaking occurred during this protracted periods of pushing the car to the max, right? Instead, all leaking completely stopped.

By the way, the car performed unbelievably well... I didn't expect it to be capable of such power.

What is this telling me? I would appreciate your feedback on this.