Wegner CH23? Original? Single Chair, Black Seat  

You can always add information to an Ebay listing after you have a bid, though you can't change your original text at all. The additional information will appear below the description. It's up to the bidder(s) to check for updates (or they might be notified by email, not sure how it's done these days) but if you want to present yourself in the best light and avoid potential problems later you can contact them to let them know.

Thanks spanky, I pride myself for my selling on ebay and only want the best for my customers, so I did take it down and revised instead of revising original listing. So many people buy from their phones these days, they may not have seen details in the description, especially below the original. Thanks for the tip, I've not had to do that before.