Thanks everyone for the replies so far.
It seems that most people use some sort of chrome effect paint, mainly for small parts,some with good results, some with not so good.
Have looked at the possibility of using the paint method, but due to the size of my windscreen and the finished quality that I'm looking for, I think the only way forward is by using the traditional chroming method.
There has been only one reply so far, ( thanks Subculture ), to my original question which I will follow it up tomorrow.
Given the size, and importance of my windscreen frame, I have decided to go with conventional chrome plating.
Just for information, the dimensions here are the dimensions of the offending frame and a couple of pictures.
Overall length 690mm, height at the centre 100mm, thickness of the metal 2mm x 7.5mm but 8.75mm for the central upright.
Mike.