Just checked the Mustang Dynamometer website and it clearly states the dydno used measures RW hp. So using the rough 0.85 calculation we get 235 crank hp and 249lbft torque, which on an 11 year old car I'm pretty happy with.
I'll clean the EGR and put a few doses of fuel/injector cleaner through her, then get another check done just to be sure.