Hi bigticket_it.
This is certainly an unusual bass, I've never seen one like it. It will require more research than I have time for tonight but I will give you some of my initial impressions.
I think it was made between 1967-70 but if I were to pick a date I would say 1968. It has a tuner configuration similar to a 1967 Teisco bass. I don't think this bass was made by Teisco so the design was likely "borrowed" from the 1967 Teisco style. The tuners are also circa 1968. The body style also has a 1968 design sense. Here is a picture of a Kawai Concert that has characteristics similar to your bass, a "violin" body style and a german carve around the edge.
Your bass also has some features that suggest a little later date. I'm not positive when the "Steel Reinforced Neck" neckplate began being used, but most late 60's neckplates were blank. If someone knows about the earliest appearance of this neckplate please chime in.
Your bass also appears to have a 3 piece neck, that is the neck is made from 3 pieces of wood glued together. Is this true?
So we have a reasonable date range, I guess your next question is who made it. The 68-70 period in Japanese guitar building is one of the hardest for determining builders. Certainly, the steel reinforced neckplate and the 3 piece neck have been associated with Matsumoku and Fujigen but is not exclusive to either. We may never know who actually made it.
I don't know about prices in Italy, but I think in the US there would be quite a bit of interest in this bass because it is so unusual. If you put it on US eBay, it think it would bring a minimum of $500. If you attracted two bidders that really wanted it I could see the price as high as $800.
I'll try to do more investigation when I get some time. In the meantime, can anybody help
