cool, as long as I wasn't missing the big red "make shapefile to JSON" button somewhere.
In fact, whilst at home watching an episode of Buffy, I realized how to do it. I have FME, which creates full fat JSON files, with the full geometry in. But I realized if I take yours, convert it, say to a dbf, in FME, see the structure, then make a similar one with the areas I want in, FME should then convert that back to a JSON with just what I want - i think:D Who knows, but I think I can see the light (as it were)
Many thanks
ACM