Hi everyone. I'm looking into Frank Miller autographed pieces, and there is a seller on eBay called popartplanet_com that is selling a number of them. He offers a COA that looks kind of useless to me. Has anyone had any experience with this seller or certifier (American Art Certifications)? Here's a link to an example:

https://www.ebay.com/itm/186032697609?hash=item2b5069b109:g:e18AAOS...

Another seller here, VaultCollectibles via empire.auctions, is selling and claiming something similar. Does anyone have any experience to share? Thanks!

https://www.ebay.com/itm/385786247049?hash=item59d2a6f789:g:0A0AAOS...