Thanks you guys (and gals?) - lots of advice, some conflicting but hey, wouldn't you expect that? :-)

She was a touch expensive (a J-40, big and beautiful) so I might try some of JustaPicker's Virtuoso Cleaner first. Or I may leave well alone - need to think on it!

Thanks again to you all, I very much appreciate you taking the trouble to help and advise on this one. :0)

Clinton - one thing, if the makers put a gloss finish on it I'm stuck with it, yes? My other guitar, a Lowden O25, has a satin finish that's just as sensitive and needs as much looking after as the Martin, so why do you say guitars shouldn't have a gloss finish? I'm truly not looking for a fight, just wondering if you know something I don't. :0) :0)

Johnny :0)