Edit heads up: in the below I clean the advance mechanism with carb cleaner and give it a squirt with WD40; I am advised by the suppliers that this is not an adequate lubrication and it should be "squirted with lithium grease", so I have ordered the WD40 version of this product. 

=================================================================================================================

My thanks to all those members who helped me get this far.

Relevant suppliers are hello@distributordoctor.com and info@pertronixeurope.com

The main challenge of this entry is getting all the pictures to fit in the total size limit, so here we go.

My Lucas 43D4 Distributor, dizzy cap removed, Ignitor removed, that red bit in the top is the remains of my broken rotor arm, I just realised. The bit had nowhere to go when it was broken off by the dislodged distributor ("dizzy") cap.

Having removed the two screws shown abobe and lifted out the so called oem "breaker plate"I see this mucky system (and a code of some sort 0752)

After a clean (I used carb cleaner) and draining and then drying of the cleaner it looks much better. Now the two mechanical advance springs are clear to see. One of these is desogned to be loose at rest and the other to be under slight tension. When the base is turned (one finger will do it easily, I then used a long screwdriver so I could see) one wants to see both springs are engaged (stretched). Mine seem ok, although I have no idea how much stretch is "good" I am told that "some but not silly" is the right measure, so clearly this is an art not a science. 

To replace the springs is possible, but the serial number off the outside of the dizzy is required, and if like mine it has been scratched out it means not that it is stolen goods, but that the specification has been modified. To discover the modification requires all the details of the camshafts (which may well not be standard BDR3 in my case). "My" builder (in 1987) told me that he bought the kit from Caterham as CKD (Completely knocked down) and all the bits fitted in his car boot. I didn't ask about the space frame. He also said he bought the engine "direct from Cosworth" to his specification, but never gave me any docs about the spec. I have been told Cosworth never deal or dealt with the public directly, so I suppose he had a tame engineer or some such, or his own access as he worked for one of the newspaper groups and was originally an aircraft engineer. Long passed away now, r.i.p. Geoff. He said he was selling me the car because now at age 70 it was too painful to get under it. That was in about 2002. Now long ago. I have rebuilt the car twice since then.

This is the same above pic after a light spray with WD4O. I do not know if grease should be applied and have enquired. 

So now we have to fit the Pertronix supplied (custom) "breaker plate" and fit it such that it is solidly fixed in place and cannot move. This is then the base for the Pertronix Ignitor II. Which is in fact replacing the Ignitor 1. I asked about the Ignitor III but he was very unenthusiastic about it for my application, without explaining why so I accepted his voice of experience. I am hoping this version manages dwell angle, but not sure - my guess is not.

So, dropping the new breaker plate in place looks like this (I see the red bit of plastic has now been removed/cleaned from the rotor holder). I have a new rotor on order from distributordoctor.com as recommended by Pertronix, who also supply these, but were out of stock so asked distributordoctor to add one to my order with them. Better build quality apparently.

So below we can see where the two original screws go (there are none in the kit as supplied). However, there is a catch, at this pount the breaker plate moves and needs to be locked in place.

So to that ned in the kit we have a lockpiece (they call it a dog bone at the factory) and is shown in my bog entry showing the unboxing. Bothe end look like the pic below except the other end is a bit smaller and fits perfectly round the spike that sticks out below and from the breaker plate. It easy enough to fit it into the breaker plate as the two levels move apart and then close up to hold it in place while dropping it into place. 

Make sure your screwdriver is a very good fit to the screws as they feel like they will too easily burr when a lot of force is applied (at first to undo them is when this becomes apparent). I didn't use any degrippant (i.e. Plus Gas), just a correct size screwdriver.

and so here we have the above now with the screws in place. I sent this pic to the supplier who confirmed correct install. I did this because the instructions are terrible. They use jargon without a glossary and the images do not make anything clear.

This is the Pertronix Ignitor II in place to test its location. There is a nodule underneath that locates it and then the screw has to be inserted in the spot shown circled in white. The black ring (shown in my unboxing entry) drops in place before the rotor arm is installed and I am told the gap between it and the Ignitor is present so no need to measure anything with feeler guages (apparent in other kit instructions). 

The red and black wires have to exit via a long black grommet which is reasonably easy to insert through the hole in the side. Just check the wires inside cannot be touched by anything. 

Adding the dizzy cap, rotor (still on order) and coil I will perhaps write a further entry.