Nice work, I've had the bits to do this for months but have been really slow about doing it!
I've got some old MK3 Golf side repeaters and bulb holders, I'll smash the repeaters and salvage the bulb locater bit, then drill a big hole in the cluster and glue the locater over the top. Thats the clusters completed, then I'll get my best mate to wire the bulb holders to the outer tail lamps, so he'll make a loom and run it all the way round the tailgate, through the grommets and back down to the outer clusters. This will make it all OEM and they'll work with the headlamp switch.