I guess that "89" could easily be "B9", under some layers of paint.
Try to get a pic of the area.
Definitely... But there's something else to the left. I would confirm Italian.
Hard to answer mate: in my opinion, a repainted, plain shell for almost 80 euros is too much. I would rather save that money waiting for something better.
Dunno... It depends: try to post some pics
Type this one WW2 Italian M33 Royal Navy Helmet Italy Original Paint MRM 211 | eBay or another ones from the same seller.
My only problem is with shipment. It very slow in Brazil and we never know, depends of international firm who will ship this and brazilian post offices...
The helmet posted to beginning post, is repainted after war, chinstrap after war. The inside could have been also done next to the conclusion of the war, the rivets it needs to see better them, from these photos it is not understood. Do you have best photo of the rivets?