Brown furniture, even with good names on are a drug on the market at the moment, It makes me weep to go to auctions at the moment and see even beautiful small pieces, ideal for modern homes go for next to nothing.
£1,000, would be the upper limit for its sale price in Liberty's. At auction, even if in impeccable condition, I would think £500. Less if it has even slight damage, like a less than perfect finish to the top. A good antique dealer or retail seller is going to spend money getting it fully restored to the level where it can command a selling price of £1,000 - and will still need to make a profit.
When we buy stock our rule of thumb is that we need to be able to sell it on our stall, at twice what we paid for it as a minimum.