Re: Wow.. I need some advise here...
First off, I hope you come back and give us an update on this.
Second, the seller has a legal responsibility to deliver clear title. You should not be hiring Italian lawyers, or doing anything to work through the legal issues on that end. It is their problem, and their responsibility to fix this. If they won't then you really ought to walk away.
Third--lesson to others reading this--don't EVER spend money to do repairs on a boat that you are still in the process of buying. I know that when you're buying a boat you are anxious for it to be yours, and you want to get started on all the things that you want to do with it. The deal is nearly done and you want to begin your list of projects, but DON'T! Not until all of the I's have been dotted, and all the T's have been crossed.
Fourth, this is exactly why it is best not to fall in love with a boat until AFTER you own it. Until the deal is done, and done completely, it is, as Michael Corleone would say, "just business." You have to be ready, willing, and able to walk away at any time if the deal goes sour.
Good luck in working this out. I suspect that it is going to take a lot of time, but it really should not require any money on your part. If it does, you are going to have to decide if you really want this particular boat badly enough to pay for something that is legally and morally someone else's responsibility. I wish you the best.