Thought I'd let you all know the outcome with this car.
I sent the ecu to Lynx Automotive for testing, they condemned it and supplied a replacement. Total cost including test of original £310+vat.
I fitted the replacement, got eml, comms and fuel pump running but still had to take the car to a Suzuki dealer to have the ecu programmed to the car, £80+vat. All ok now customer happy and even with my labour charge the bill was not to hefty.
Thanks anyway, Colin.