Stain on top of a Vodder cabinet, what to do?  

Hi all,

I recently had the pleasure picking through a little house filled to the rafters with furniture, carpets and all types of weird things. The last owner brought stuff together from different houses/relationships in this one, small home. I obtained some great danish pieces which stood camouflaged amidst all sorts of things a layers of dust.

One surprise was this wonderful chest of drawers by Arne Vodder for Sibast. I have a matching sideboard with tambour doors at home, so happy days 🙂 The chest is in superb condition, except for a stain in the top. I don't know what gave this discoloration, was it ink (hope not) or a waterstain which oxidized the wood?

As the surfaces are and general color is so good, I don't want to harm it more when tackling the stain. What should I do???
Which way to go and what steps to take first?

In the picture the chest of drawers and a complete over-the-top etagère in chinoiserie style, carved and painted, which I also obtained from the same adres.