Both headlights have now been wired up and are working perfectly. The only concern I have is whether the dip beam pattern of these headlight is compatible with the requirements of the Single Vehicle Approval test. Here are some pictures showing the beam pattern in dip and main beam.
Update: What I ended up doing was rotating the lens within the housing to give the 15 degree kick up at the left side as required for MOT beam testing. This was accepted at SVA and has passed a couple of MOT's since. Interestingly, I don't think I've actually driven the car at night so I've no idea how effective the lights actually are in practice.