It looks like there is a 503 (flat bed that looks like a Supernova probably made in Italy) and a 503FA (free arm probably made in Taiwan) that are different from one another. I found this one
https://manualsoncd.com/product/necc...uction-manual/ for the same price and it shows that it is English.
Interestingly, the
Necchi model list only shows the 503 as being made in Taiwan and doesn't have the 503FA listed.