Well it's all back in one piece and appears to be working - Pizzas for tea.
If anyone has the same issue, there are 13 screws that hold the unit in place; 4 at sides of bottom oven, 4 at sides of top oven and 5 at the top edge of the top oven).
Oh and there was only the the one panel...
My first post... Guess what, I'm in trouble!
While attempting to replace the element on our built in Zanussi ZBF865X fan oven, I accidentally let one of the wires that connect the element slip back through the little hole into the back of the oven.
I've tried to hook it and pull it back...