Good question....and if so, what DID he use in the studio?

No, Bonham only used wood kits in the studio. The first album was recorded with Slingerlands, the second and possibly third were recorded with he thermogloss Ludwigs, the fourth album through Presence were recorded using the green sparkle Ludwigs, and there's a chance a silver sparkle Ludwig was used on In Through the Out Door.

No he did not, All recording were his wood kits.

I'm sure there are others who can give exact dates, but here's a ballpark estimate of things.

September - October 1968: Led Zeppelin recorded

By March 1969: Bonham receives thermogloss Ludwig kit

April - August 1969: Led Zeppelin II recorded

May - August 1970: Led Zeppelin III recorded

By June 1970 - Bonham receives first green sparkle Ludwig kit

December 1970 - February 1971: Led Zeppelin IV recorded

December 1971 - August 1972: Houses of the Holy recorded

May 1973: Bonham receives amber Vistalite kit

February 1975: Physical Graffiti released, composed of recordings from July 1970 through February 1974

November - December 1975: Presence recorded

By April 1977: Bonham receives stainless steel Ludwig kit

November - December 1978: In Through the Out Door Recorded

There's a lot of overlap, but if you listen to the records it's clear he's playing wood shells. The only question I have is whether the stainless steel kit made its way into the studio. There are a number of later tracks that I feel like sound like they could be stainless, if not just larger drums (the 15x12 rack, primarily).

The stainless kit was used live only. Jeff Ocheltree & Jimmy Page have both confirmed that the green sparkle kit was the kit also used on In Through the Out Door......

The silver sparkle kit was a 6-ply shell kit that was used at his home in England. I believe that Jason Bonham has also confirmed this. It was never recorded with or used in a live concert.

Just for fun, I give these pics of John Henry on other stuff: a different Vistas, what appear to be North, and Gretsch. Don't know if they were taken in Led Zepp rehersals/recording (specially the North set) or even a private party.

No, Not any of these kits were used on zep albums.

The striped vistas were in his home. The "North" drums you suggest are actually Staccatto drums and were used on a Paul McCartney session. He never used those on any Led Zep album as they weren't his! They were just what was in the studio that day when he was asked to do the session.

And before anyone else suggests this kit, they were used on a German TV shoe called Beat Club and were a rented set for the show as well.....yes, those are Sonor drums, also never used on a Zep recording session.