Thanks for the replies, for the no2 end with the glued in cranked nem box I have warmed up the coupling and tweaked it upwards a few mm this has made the coupling/uncoupling spot on,
For the number one end I have fitted an offset coupling with the hook removed,hook pin moulding shaved away, and the front lip of the coupling bar shaved off then fitted it upside down in the pocket.
Ok, no hook at this end but coupling is fine and I can leave the original loco coupling in place,
Best regards
Sultan