nik, i would say by looking at the photo (as previously stated) that you have had either an safc or emanage piggyback unit hard wired into the loom, and then wires have been re-connected when removed!
what you really need to do is do away with those crimps and solder the wires back together then put some heat shrink covering over the joins, as the crimps can alter the ohms readings and give false info to your ecu.
is bad how the guy said it had all that stuff fitted but it hasnt! but then again if you havent paid over the odds for it, its just a case of sorting the bits out that need doing!
think sideways steve was a one hit wonder and just came on the sites to flog the car, so its always more of a gamble with these type of people, but in all fairness to him 'he may have been told the same as you when he purchased the car'
ecu looks standard also