I did enclosure for Lucas ingition used in Jaguar MKX (but it will be probably similar on several british cars from that time as well).
Reason for making is worn clamps in back and body of ignition wasn't hold together / wasn't work properly.
It is just two rings for screwing together with washer that makes pressure to back of iginition.
Due to fine thread, I get good results using a resin printer (SLA).