Led Zep - Ramble on drum intro

[Lexer]

This has been discussed before as to whether Bonham used a drum stool or a guitar case for that opening drum part on ramble on. My question is this? When he goes from hitting the drum stool or guitar case, does he somehow go straight into the regular drum set or is that just a special intro that was added in the studio? In other words, how would he transition from guitar case to drums if he played that song live exactly as in the studio ? It seems as though it would be an awkward, cumbersome type transition.