At the twist grip end there should be a ferrule. These are standard, but come in 2 sizes. The easy approach is to order one of each and see which fits. If you are really lucky, the spare one might fit the carb end. I don't know what was originally fitted here as I have made my own carb end brackets as my Squares have come without them.
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.