I was kind of surprised to see that thread disappear too.. Someone started posting screen shots from the movie, which clearly didn't match the item in question. It still could have been production made, but it really didn't seem to be screen-worn, at least by way of screen-matching proof. Doesn't mean it wasn't used in other shots though. Just because it doesn't match some shots doesn't dis-prove it's use in the movie totally....
But, in this one instance, I can explain his devotion to the COA:
Hollywood History isn't run by an 'unknown bloke' that just put Hollywood in the title. Wesley (the owner) is a well-known and well respected prop collector. His store might be newer than Propstore or Screen Used, but he runs it with the same ethics. A COA from his store is a guarantee of authenticity in the sense that if it's proven to be not authentic, you will get a refund for the item. And he doesn't just put stuff up forsale on a whim. To me, a COA should never really be used a proof that the item is real, but more of as a guarantee that if it's proved to NOT be what it says it is, you can get a refund.
That's why I hate all the 'I'll throw in a COA too' type things on eBay... Oh really? And that COA of yours means you will give me a full refund 2 years from now if I find out the item is fake? 'Oh, no. All sales are final, sorry.' Then I have a roll of toilet paper with more value to it than your COA...
What I want to see on a COA is contact information and a paragraph stating that a 100% refund is always GUARANTEED should the item be shown to be fake or mis-represented in any way. But, as Jason pointed out, that's pretty rare... For eBay auctions, 'COAs' offered by sellers aren't any more valuable than a screen shot of the auction listing... It a certificate of authenticity that you did indeed buy the item on eBay.
