I think it is a nice looking bike, where the owner put quite some love into it. It looks like a 175 CS with the OHC head. The half fairing is looking like it is of a CSS. Alone starting with the tank (350B, 125 RSS, 150 GTLS ?) many parts seam to be not original, not even out of the time. So if You find someone who wants to ride it I would think might 3000 to 4000 USD. Collectors on the other hand will be probably not interested, at least not for much higher prices. Finding a original tank, seat and so on would might raising the value.