Apart from rolling the car onto the roof, or superglue, what is the official way of keeping the thermostat in place whilst you get the elbow and "o" ring back in place past that wretched power steering pump boss? Mines a 1.6 so the 1.9 might differ.
i 'assemble' the o-ring and t-stat into the lower coolant flange and then carefully insert it that way.