Italy taking London?! Now I’m intrigued! That sounds crazy awesome. Have no idea how it could work. A risky move, no doubt. Like letting Italy clean up Paris after Germany does the dirty work. I’m a big fan of non traditional strategies.
I assume the German player will destroy the French DD and CA in SZ91 on their first turn. The UK could make an ill advised attack on the Italian fleet, and might not destroy anything(flip the BB?) and in return lose a FTR and a TAC.