Rolling stock on the L&B had a coupling hook at the Lynton end only. I removed the hooks on the Barnstaple end of all my stock with reference to the drawings in The Lynton & Barnstaple Railway Measured and Drawn and photos in other books. This made it much easier to couple and uncouple stock.
As supplied the couplings on Accucraft stock are at various heights. Those on the coaches varied from each other and are difficult to adjust. My first act was to fix the couplings on the coaches directly to the headstock as described here. That stopped the coaches from uncoupling from each other and fixed the coupling height.
Before and after the modification to the coaches the hook on the locos sometimes uncoupled from the coaches. I am still playing with the following modifications but they seem to be working at the moment.
add a washer between the head of the coupling fixing bolt and the coupling bracket behind the buffer beam. This lowers the coupling.
exchange the hook on the loco for one from the coaches. This removes the disc on the dropper which catches on the cow catcher and restricts movement.
tighten the bolts which fix the coupling bracket to the buffer beam.
The couplings on the wagons are all different. I have adjusted the ones on the Accucraft 4 wheel wagons as described here.
Eventually I would like to introduce auto coupling, possibly with permanent magnets in the track, which works well on The Hambleden Valley Railway