the main jewels remained in the vault of the Bank of Italy and there is or was a court case about them.

Umberto and Marie-Jose did divide up the jewels they did take with them so Vittorio-Emanuele did not get them all, his four sisters each received a share. After her divorce from Robert de Balkany princess Maria Gabriella ended up selling a number of her jewels that were mainly from the Belgian inheritance of her mother. I think I remember reading that the youngest sister Maria Beatrice also sold several pieces but I don't really know what pieces she is supposed to have sold.

Maria Pia's wedding tiara was one that came from Queen Margarita and was sold into a collection.

I don't remember seeing any of her descendants wearing Italian jewels. Her oldest set of twins are men and they are unmarried so no chance for any jewels there. Her younger set of twins include a daughter who I've not seen in any tiara of her mother's line and her brother is in his second marriage. The first only lasted a few years and he and his current wife live a rather quiet life. They don't seem to attend many grand events.

The second set of twins has the complication that legally their father was their mother's first husband making them members of the Serbian Royal House but that most likely their biological father was their mother's second husband a born prince of Bourbon-Parma.