made card templates for the front and back by laying a piece of
construction card over the frame and drawing around it. I added a
little extra for folds for joining purposes, then cut it all out,
folding the card as appropriate. Nothing to it really.
Once done, I folded it all flat again
and did the same trick with spraying left-over spray paint around
the edges to mark where to cut. Then it was the hard labour with the
metal scissors again that kept me busy for a while. So long as you
wear protective gloves the sharp metal edges are not a problem.