Hi! I have the Yahoo Necchi group. The 539 is a post-Italian model (we only discuss the vintage Italians). I don't know anything about these but a list member who worked for the Necchi distributor posted the following about it. (It comes up periodically on the list and at one point someone had one that said Made in Spain but this is the most we've ever been able to find about it):
"Actually the 538 & 539 Necchi models were not made in Italy. They were made in Japan and were probably the first Asian made machines with the Necchi brand. They were manufactured by a factory called Zenith Nito. They made a number of Necchi machines over the years.
At the time these were distributed dealers were asking for machines to fight off the inexpensive Japanese machines their competitors had. I've seen this model in the files here listed as Italian and I just wanted to set the record straight.As for the feet it takes a standard low-shank foot or accessories. These are available widely.The bobbin case is a standard 15 Class one also. If it falls out the only reason is you don't have it in properly so it locks onto the post of the shuttle hook. The 'finger' on the bobbin case must be at the top and go into the cut-out for it on the race cover."
This is a site I found that talks about his 539 and has pics....from the pic it looks like a standard Japanese model with the knob on the front of the bed that lowers the feed dogs.
http://possumjimandelizabeth.com/xht...ng_necchi.html
Hope that helps!