Both distributors were removed from 4.2l XJ6 blocks. I believe the one on the right is a 22D6, but what about the one on the left? It has a much shorter body originally fitted to what?

 

... or bring the ignition system into the present century with something like:

https://trigger-wheels.com/store/con...n-uk/p141.html

EDIT: Sorry, I posted this in the wrong thread. I'll leave it in case it's of interest.

 

the one on the left looks just like the one in the 3.8 liter engine of my 1965 S type.

The 3.8 liter was fitted to many Jaguar models, the E type, the Big Saloons, the Small Saloons, etc. up until 1967,

and from 1966-on, the 4.2 liter in the 420, 420-Grande, and in the XJ from 1968-on.

 

Looks like the date code on the one on the left it is 1971, so not many options if it is a Jaguar distributor. I don't know if it is interchangeable with other British cars of the era, such as a TR6

 

could be a dated spare part.