Went to JabbaSport for a rolling road remap yesterday. It turns out that my car is a bit unusual and the only one like it Michael has seen.
It's a 99.5 B5 1.8T Sport which is drive by wire, but has the pre face lift ecu - so no diagnostic port re-map. It also seems to have a K03 turbo but with larger internals.
Before - 164BHP After - 223BHP
Will post the torque when I get the plots.
Well happy with that for an otherwise standard car !!!