Are we talking .455 Eley or .455 Webley?

I have a Colt New Service in .455 Eley , aka .455 Colt.

The .455 Eley case is longer and uses a heavier bullet that the .455 Webley MkII.

I recently bought several boxes of Dominion brand .455 Eley and .455 Webley at a flea market. Judging from the boxes , the Dominion/Eley stuff is rather old and two boxes of the Fiocchi is fairly recent.