Re: 59 vs 57 classic.
'59 - Lots of treble and bass, scooped mids. Sharp high-end. Tight low-end. Well defined, articulate.
Neck model can be boomy (especially in LP's); bridge can be a little bright and thin. These are remedied by lowering the bass side of the neck PU, and using 250K pots or a warmer magnet in the bridge.
'57 - Lots of mids, rounded high-end, loose low-end. Warm.
Neck model can be dark and muddy; bridge can have a funky thin 'ribbony' sound. These are remedied by putting an A5 or A4 in the neck, and an UOA5 or RC A4 in the bridge.