Code:
alias +spyattack "+attack"
alias -spyattack "-attack; last_disguise"
alias spyslot1 "slot1; bind mouse1 +attack"
alias spyslot2 "slot2; bind mouse1 +spyattack"
alias spyslot3 "slot3; bind mouse1 +spyattack"
alias spyslot4 "slot4; bind mouse1 +spyattack"
bind 1 spyslot1
bind 2 spyslot2
bind 3 spyslot3
bind 4 spyslot4
last_disguise is an alias defined like in the original spy disguise scripts. This scripts starts disguising you every time you stop attacking with anything else than your knife (which sometimes gives you instant disguise).