I have just done this to my 110 and I’m the process of doing the same to my station wagon. The lights you need are the later style “sealed” unit ones (indicator is in LR048188, I have just ordered some). They were also fitted to 300tdi not just the td5. As mentioned above you by at
@Def90man you will need some of part number RTC3745 to fit into the square holes to then screw the lights to. I fitted led side and rear lights to mine form rdx and 12 months later they are still functioning perfectly well and I have no complaints but I left the indicators as standard bulbs. Something else to be aware of If you do go for the later style you may need to make the actual large hole in the Ali panel Behind the capping larger to accommodate.
The lights you have currently should earth through the wiring loom with the brass tab as a back up. But the loom earth point is just a ring connector self tapered into the tub behind the corner panel. I replaced these with a bolt through the tub with another wire underneath going to the chassis to give a good solid wiring earth. This then means you can use the adapters above as the loom earth they rely on is a good reliable earth.