While I am happy with using Microtrains couplings for most of my 009 stock with its advantages in shunting, I have realised that fitting them to my Heljan Manning Wardle is too difficult but also unnecessary. It will only be likely to run with suitable coaches such as the Peco ones, and so long as it can couple up reliably and uncouple to run round the type of coupling doesn't really matter. So retaining the "standard" 009 coupling is easiest, except that the ones factory-fitted to the loco sit too high, and I've been unable to adjust them until they couple reliably to the Peco coaches.
The Peco coupling works normally, but when positioned over a magnet the staple pulls down which lifts the loop. If there are two loops a pair of magnets might be needed, but I only want to uncouple the loco (without loops) from the coaches so this should work well with one magnet. Here a tiny 2mm x 2mm neodymium magnet is held between the sleepers with blue-tack, a Greenwich magnet would be ideal but I don't have one, I will try a slightly longer magnet set under the sleepers which should work with less accurate positioning. However, the experiment shows this is a simple mod to add magnetic uncoupling capability to the standard Peco 009 coupling. It might work with other types so long as the loop is not magnetic (the Peco loop is plastic). The coupling on the Manning Wardle is level here and couples to the Peco coach, but does still look slightly high in this photo, a quick adjustment with pliers should fix that.