Try here http://shop.trident-uk.com/sailing/E...ccesories.html
and see if there's one that will fit.
I bought a whole pile of end fittings and made up a killcord that so far has fitted every boat I get on.
I wouldn't recommend putting a tie-wrap around it (suspect that was a tongue-in-cheek suggestion from Chewy!) - probably wouldn't disconnect properly if you ever needed it to do it's job for you.
However - and despite all the above - I'd have to say that if it was me I'd buy a whole new fitting including a new cord. They do degrade in sunlight, and at the end of the day it's not a lot of money for something that might save your life