I bet he didn't sit in it much, if at all.
Elle, I think it's a good idea to be somewhat skeptical about this kind of sale. As exciting as the notion is initially... it's definitely a good idea to do some homework about this chair before anyone thinks about investing money in it. That's one reason why I asked about the auction house... if it's a well known national or international auction house that can be a very helpful sign. If it's somewhat unknown, I might continue to be skeptical. Also, as counter-intuitive as it might seem... certificates of authenticity are not usually considered very useful documents. Essentially, anyone could fake a certificate of authenticity. It's not a substitute for finding out as much as possible about where the object came from... or, for example are there pictures of Heath actually sitting in this chair somewhere out there, etc. Or, if inspected in person, would an observer immediately notice that it doesn't have enough really evidence of daily usage or wear-and-tear to be credible, etc.
Anyway, it may be a great bit of Brokie memorabilia or it may not. But, in any auction situation, it's best to be cautious.