Hi Mel,
you could cut out the vent holes so the new panel would weld in under where the rubber seals are on your series bulkhead vents, keep the vents and hide the welds. Swap the windscreen mounts on to the new panel and add some of the plastic blanking plugs for the extra wiper holes and your done. If only it was that quick and easy, would take a lot of time to cut the old panel out and add the new one in but would look good when finished.
An ideal way to get you through the cold dark winter evenings!
cheers,
Stevie.