Finally found the latest coolant leak. It's at the bottom of this thermostat bypass hose. This is now going to be replaced when I do the water pump and timing belt. This is the fourth hose to need replacing (plus a connecting pipe).
A new hose has been ordered. Given that most of the hoses have now been replaced, I'm going to replace all the remaining original hoses left as well.
Also fitted the Jass Performance drift button that I got for Christmas. This allows to handbrake to work without the ratchet locking. To make the ratchet lock, you have to pull the button out. Fitting is simply a matter of unscrewing the hand-brake button and removing the spring behind it, then screwing the new aliuminium button in place.