This sort of 'tortoiseshell' effect - has certainly been something produced by the Italian Vincenza factory (that's if they're producers and not simply distributors). Had you not said '30 years', then :or: would have been a possibility. I can't see the base clearly, but it looks as tho the finish is simply flat, and without any pontil marks. Appreciate this not particularly helpful, but might be worth looking into. For whatever reason, this colourway of caramel over pale coffee, seems not to have been much used in the past - perhaps it looks rather 'kitsch'.