BB thread gone. Options

You don't want to have your BB re-threaded Italian, really, you don't. It has right hand threads on both sides so the non-chainwheel side cup is always trying to wind itself out.

And anyway, I'm not sure it can be done as Italian BB shell is bigger than the English. You could sleeve down Italian to English but not the other way round.

If the frame is worth it, I would bite the bullet and have the BB re-threaded properly. If not then go threadless BB

Funny I have had my italian bottom bracket in for two years and it doesn't undo itself.