They do, occasionally, list things already sold. Not sure why, maybe it's just to have a record of the sale for the consignor. If a sale arrangement has been made before the item is listed, you'll never have a chance.
(Not saying this was the case, but I happened to up at 2:35am PST this morning, and it was already showing sold. I think 2am my time is the listing time for UK items.)
All they are concerned with is selling the merchandise, so it doesn't really matter to them about a 'preview' period or anything... As long as it sells. I assume they have some regulars with known collecting habits that they will cater to sometimes. You might call them now and ask if they have anything else from LSOH if it's something you are interested in, sometimes they get multiple items from a property and list them one at a time.
