I've experimented with Dapol Easi-shunts- admittedly on Roco and Tillig stock as my Scotsman set hadn't arrived yet. The NEM pockets have bigger gaps than the N-gauge pockets, but the plastic is fairly rigid so squeezing them together with narrow pliers got the Easi-Shunt to sit in happily. O Hornby Radius 2 the couplings performed quite happily, no issues pulling or pushing the train round the layout. These are the nearest to Kadee couplings you will find. My Scotsman set has arrived so I might try them between a pair of the Pullmans- the loco has had to go back to Hornby as it was missing the wheelset from under the cab.