Hi Michael,
Ok, thank you
herewith a sketch of the portrait by Dosso dossi of Alfonse d'este, duke of Ferrara C.1510(Brera gallery Milan). Please have a look at the Pommeltype and hilt decoration.
the pommel is Norman type 12 and is commonly used between 1515-1535.
the tumbring counter guard of the hilt I can not explain but think 1515-1535 is too early.
best regards