Funny story...
I'm a member of several Zep forums. Years ago I bought my wife a coffee table book about Abba, and inside it, in the chapter on the opening of Polar Studios, was a photo of the cover of the brochure advertising the new studio. The picture on the cover depicted one of the studio live rooms, and prominently showed two drumkits - one green, one silver or chrome, in "Bonham configuration" .
The text checked out: it mentioned the dates of the photo session, and the recording dates of the first band (apart from Abba) to use the studio - Led Zeppelin. They were close enough that it seemed reasonable to assume these were indeed Bonham's kits on the cover of the Polar Studios brochure.
Feeling quite pleased with myself I posted a scan of the photo, plus my detective work, on a couple of Zep forums. Photos of the recording sessions were very, very, rare so it got a very good reception.
Until...
The webmaster at the official forum posted in my thread to say that he had shown my photo to Jason Bonham, who had stated that these were definitely not his dad's drums. Well, I wasn't convinced , and I still use the Polar Studios brochure as my avatar on the Zep forums, but that effectively killed the excitement about my "find".
Until...
When the remastered expanded CD of In Through The Out Door was released it came with a booklet containing, amongst other things, studio photos from the sessions. Can you guess what's coming?
Yep - there for all to see were Bonham's drums. The same drums, in the same room, that were on the brochure cover I had found. I was right all along.
You can see at least one of these photos in this video series.
My tiny little contribution, lol!