Help with tuning my MY03 WRX (non-USDM)

[Scoobtastic]

Hi, could you far more knowledgable people help me with tuning my MY03 WRX (non-USDM).
I've downloaded the rom (should be attached to this post). It's been mapped before when it had a few exhaust/engine mods and for super unleaded petrol, but then I had it remapped back to normal unleaded due to changing my job and a longer commute.
Anyway, now I'm back running it on super unleaded I'd love to get back to the previous performance of the car (but without the expense of having it remapped yet again!).
I'm not expecting miracles here, but I'm sure the boost could come up a bit along with the fuel mix.
Any help (and an explanation of what you changed) would be most appreiciated!
Matt

MY03 WRX Non USDM