The left guitar is Dave's black Floyd Rose Strat that he has played since 1999. It has a Hot Rails/JB jnr/Black Hot Rails pickguard, but in 2013 Dave experimented with DiMarzios in rehearsals, but swapped back to Hot Rails for tour, The right guitar is the Signature model prototype, with added Floyd Rose. It was used as a secondary guitar in 2009.
Here is the Kossoff strat with some kind of locking tremolo. Mind you, that in this picture it probably sports a different neck. This system was on the guitar only for approx. 2 months. It was swapped back to the standard tremolo and original neck during World Slavery Tour.