I spoke to him a few days ago, the lid's got a cut out for a protein skimmer. If I could find a replacement lid somewhere I'd snap his hand off - even at the price he's asking - but since it's out of production I can't find any trace of a replacement lid, and can't think of an obvious way to replace it whilst still maintaining the aesthetics.
Unfortunately there are a few with similar - missing lids or cut outs. I'm checking Aquarist Classifieds and ebay every few hours so hopefully I'll get one eventually.