Chris, I didn't ask since it's none of my business but I would think for a collection of that size something must have been put in writing.
Gary collected for decades and as a dyed-in-the-wool OO7 fan, he bought whatever he could find, even if he already had it. He had over 700 copies of the Fleming / Amis / Gardner books in every language and configuration you can think of. His mindset was if the book was about Fleming / Bond / the films, even if it was a marginal mention, he bought it. Same thing with the posters. American, British, Swahili, it didn't matter. If he could afford it, and he usually could, he bought it. When he retired in 2016 and wanted to move, the thought of bringing all that with him was too much. Plus his job didn't offer a 401K or decent retirement package so the Bond collection was his nest egg. He wanted to get as much from it as possible and I don't blame him. I know that the first Heritage offering in 2016 was totally satisfactory with him since it was the cream of his collection. Later on, when Heritage slowed the flow from his collection he got a bit antsy.
Originally he said he didn't want to send the posters to one auction house and the books to another. He wanted it all gone in one shot. He didn't want someone from one auction house to look at the collection, take all the first editions, original page proofs and scripts and leave the paperbacks and foreign editions. I can't blame him there. The posters would have been easier. Had he sent them to Bruce, most if not all of them would have been sold by now. How much of a profit he would have realized is unknown but Bruce could easily have had a huge auction of just Gary's material alone.
As it stands today, Heritage has it all and is slowly offering it up. I'm sure they are mixing it in with other Bond material they receive.