gaffer tape, weld it or even pop rivot a plate over it(the whole area) p.s have you checked the sills
welding best option you could bodge it with filler or fibreglass and repair later if you keep disco.
A fibre glass patch will work.
Ok then thanks for the advice as always guys appreciate it!!
I've got the same problem, thinking of taking out the windows altogether and fitting some chequer plate panels instead? Or would that look gash?
Do you even need to ask?