I just got back from Olly's GTG, or more accurately, Mrs D's ML just got back from Olly's GTG!!
She's had the manifold gaskets replaced, new thermostat, new glowplugs and the handbrake adjusted. Super drive home, and without doing anything scientific to confirm I suspect she sipped a little less fuel on the way home.
Thanks to Olly and Jack for their top work, to Ringway for getting me home on Saturday night, and everyone at work for driving me around ever since!!