Kitmaster Mk 1 Couplings.

 As these three will run in a fixed rake, there is no need to provide uncoupling betwwen coaches- only the outer ends.
It needed something simple and this is what I have come up with.
A dressmakers brass pin is soldered to the loop and bent through 90 degrees. The upright on the loop prevents buffer lock and anyway these will only be pulled not pushed through reverse curves.
Simples!