Thanks Simon. I’ve fitted Kadees to EasyBuild and JLTRT kits in the past. The problem with the Maunsells is that Slater's have worked hard to make the underframes true to the prototype - and there’s not really much room left to fit the Kadee coupler box. It’s a similar issue I encountered with the MMP RMB - not easy to fit the third party coupler system when the kit is built like the real thing. Having experimented further, I think I can continue to use the kit couplers.