A good new old stock DMBZ distributor cap for a range of early Jaguars including the E Type S1 XK150 and some of the early MK2's Jaguar part number 6478

It's not a genuine Lucas one but Commercial Ignition was a recognised maker of aftermarket ignition components.

The cap comes with 7 acorn nuts C11906 and 7 copper washers C5452

The cap alone from SNG's would cost you about £43