Hallo John,
the 5th picture shows the capholder screw and seems to exactly fit the pictured fuze. The 6th picture, with the screw removed, shows the firing-needle. I think you would call this a concussion time fuze, where the powder train is ignited through set back force upon firing. The system used for early cylindrical projectiles, where the propellant fire could not reach the fuze. The lower part with the powder train, like in your nice picture, seems to be missing. I'm not conversant with those early british fuzes and have not seen one which is made in 2 parts (seperate powder train body).
With kind regards,
Bellifortis.