Thanks for the feedback and suggestions guys, I've had a message from the train seller and he is going to see if he has any spares so I may be able to get one that route.
However I'll also check out that seller Sun, it would be handy to have some spares anyway for all sorts of reasons.
I had already considered cannibalism, but unfortunately all the trains I have with the appropriate couplings are currently working or repaired by me lol!
Oh, and I have got a triangle bit already, needed it for another repair job 🙂