This was the band's first headlining international tour and featured a far larger equipment. The famous 19th and 20th November 1974 concerts at the Rainbow Theatre have been professionally filmed, and both the video and some extraordinary photographs by Richard Paul-Jones (link) provide some nice insight into what they used at the time.
Additions were a lot of piano-based songs, plus a short excerpt from Bring Back That Leroy Brown on which Brian swiftly changed, with help from his roadie Richie Anderson, from guitar to ukelele-banjo, and then back to guitar.
Triangle [Killer Queen]
Electric six-string guitars
Ukelele-banjo [Leroy Brown]
Electric bass guitars [used interchangeably]
Public Address system
What about the recording sessions?
The multi-track contents from Brighton Rock (which leaked to the public in 2008) show that the song has about thirteen different guitars (e.g. the outro is played on 6-7 at the same time). One of those guitars is definitely not the Red Special (it's not a matter of EQing or effects, it's clearly not the same guitar), and sounds exactly like a Stratocaster, which makes sense - Brian used his home-made guitar 95% of the time, but occasionally tried other things. For most of the song, including the solo, and for most of the album, Brian of course used the guitar he made with his father. Other documented instruments besides what they also used live were Ludwig Ringer 28" and 30" timpani for In the Lap of the Gods, Abbot Monarch ukelele-banjo for Leroy Brown, and different pianos depending on the recording venue: Yamaha C-7 at the Coach (Tenement Funster), Bösendorfer 225 at the Quadrangle (Flick of the Wrist and Lap ... Revisited), Bechstein III at Trident (Now I'm Here) and Bechstein D at Wessex (the rest of the songs).