Andrea — I have done several threads here on vintage Italian melodicas, including a detailed description of one of my refurbishing projects linked below. If you search the forums here for “Italian” or for brand names such as the two you mention, you’ll find more photos and comparisons. The reeds of the vintage Italian models are very similar, in some cases the same, from one brand to another. And they are also similar to those of the La Clavietta. Thus the similarities in sound.
If you acquired yours in good playing condition, that’s very unusual.
There are much more recent Bontempi models that are not at all comparable.