Helmets that look OK with vintage Japanese bikes

That AGV X3000 is just lovely, isn't it. Smaller overall shell size than the equivalent head size for the Bell Bullitt, too (as I understand from a Youtube review). Probably the closest to Bubba Zanetti's helmet in Mad Max (1979). 

We've got very few motorcycle gear stores here in the UK (whole country's in a spot of bother re: retail as a whole; there used to be many, many bike gear shops but they've mostly closed now) but I'll try and pick one up in Spain soon, unless I see something even better. Nothing beats actually seeing it in person and trying one on. Will look at Arai basics too (I think it's a nice shell shape, albeit pricey).