Morris Minor Owners Club

Just get a non-polarized capacitor and connect it across the connections to the points. What it does is it allows the high frequency harmonics created by the sparking across the capacitor and shorts them out on the other terminal, thus removing a lot of the 'sparky bits' which reduces the oxidisation on the sparking terminals and extends their life considerably. This is why we have an ignition condenser across the points terminals.

an ignition supression capacitor should do the trick, or just get a 0.1 microfarad one.

The difference is that the ignition capacitor is designed in to
the distributor. Where exactly are you going to fit the new
capacitor in the pump?? I think it would have to hang outside
which might give some problems?? all the later pumps have double
contacts and seem to be quite reliable if the points are cleaned
very occasionally.

The 0.1 microfarad capacitors are quite small and should fit easily behind the cap (although I have not checked) as they are about the same size as your finger nail and have stiff wire legs to bend and hold them in place.

It would not matter if it did hand outside the cap as it is not dangerous and it will not stop functioning even if it is submerged in water.

Yes, worth a try but the moving contact on the pump has quite
a long travel so the capacitor lead to this side will have to be
super flexible( like the braided wire in the distributor from the
side contact to the moving plate).

Just connect it between the positive and negative feeds to the pump, as close as possible to the source of interference (points). It will have the same effect.