Thought I'd post this over in eventing as well... I just got a helmet from a vintage store in AZ; the tag inside says Nina Barbour. It was black, I assume, though faded to brown; has a black ribbon around the base, with a silver buckle on the side. More helmet than hunt cap-ish; pretty sturdy and has a solid snap chin strap.
I can't find anything about Nina Barbour helmets... does anyone know anything about them? Approximate time period, etc.?