Is the Fiume Savoy shield stamp official?

Under the Free State of Fiume issuer on Numista the banknotes are marked “CITTÀ DI FIUME”. But on eBay examples are selling with a black Savoy shield stamped instead (below).

were these official banknotes issued by Fiume? They aren’t in the Numista catalogue.

Pick S107b https://en.numista.com/catalogue/note217954.html Numista page indicates handstamps and overprints should be on Hungarian language side. Note seems to indicate that overprints/handstamps on German side are not official.

Will