I met someone who's strung Andy's racquet, and according to him these are his specs:
I know that a lot of players do have paint-jobs done on their racquets, but he's completely certain that Andy's racquet is a standard Head iRadical (with some customizations)
Head iRadical MP Racquet...
with iPrestige Cap Grommets (Notice that the outside frame is all black)
Alu Power Main Strings strung at 61lbs
BDE Natural Gut Cross Strings strung at 62lbs
L3 4 3/8 grip size with a Karakal PU Grip
I would imagine that his string tension probably varies slightly depending on what surface he's playing on.
Just incase anyone wanted to know