yes, all AUM's have a KO3s, so i guess you are missing some hp! As yours is a very early AUM, i have heard that there is a small chance it uses the KO3, not sure how much truth there is in that though. Mine is a Y plate AUM, and i have a KO3s... Easy way to tell, get under the car, have a look at the turbo and count how many fins/blade the turbo has, if you have 12 - KO3, if you have 8 - KO3s then get it checked out and see why you haven't got more BHP!!
Then you can consider your Re-remap
speak to Nick at R-tech, if he has a look at it, i'm sure he'll be able to tell you whats up, have you got VAGCOM, if you have, plug it in see if it throws up any fault codes, if not i'm sure a local mechanic will have a universal diagnostics reader, the fault should still show up.