Couple more jobs tonight:
One of the mounting points on the undertray was broken. I've cut a chunk out of an old broken tray to use as a repair piece.
Stuck the repair piece on using panel-bond. This is a structural polyurethane for sticking bodykits on so it ought to stick the plastic quite well but still be flexible. This is rather experimental so we'll find out in a day or two if it works!
With that done, moved on to the missing fridge bracket. I made a new one from 25mm aluminium flat bar, bent to shape. Using a 'mandrel' to get a radius on the bends:
Rough shape
I needed to tuck the front of the bracket in round the shape of the fridge to get to the mounting holes so used a couple of bits of steel to form a kink
Wrapped the completed bracket in anti-rattle felt tape and its ready to fit
Here the car threw me another little challenge. I was expecting the sheet metal to have captive nuts of some sort, but it turned out they were just through-holes. Back seat out then, to get a nut on the bolts!
Employ Mr Tickle to hold the bolt in the boot and the nut in the cabin
at the same time 
Bracket bolted in place and secured to the fridge with plastic rivets
And finished with it's cover panel
Pretty happy with how that turned out
