Guy in the bodyshop [who is somewhat OCD to be honest] reckons it's "too far gone".
Your idea of a Capri could work Paul. The bulge is quite long so would need to be off a 3l I guess. This looks "similar" to mine http://www.ebay.co.uk/itm/FORD-CAPRI-MK1-3000-GTXLR-BONNET-OFF-A-FACELIFT-MODEL-/261488436218?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3ce1ece3fa
The bonnet above is £130 at the moment. When combined with the cost of a Mk1 Escort bonnet, the cutting, welding and filling involved would I be just as wise to get a Carbon Fiber one perhaps?