Night of Masks by Andre Norton

1973 3rd printing by ACE. Very good condition with some slight edgewear. 
 
The story concerns Nik Colherne, who aids in a kidnapping to win a new face to replace his scarred one. He gets his new face and fights to free the kidnapped boy - and himself - from the Thieves Guild.
It is a rattling good adventure story which should be relished by science-fiction buffs of all ages