This is a long answer to a simple question.
I don't think there were many (any?) Green NG's in the UK, which is why I asked.
Re the all black wheels, I think so. Someone else may know differently and I am not an expert.
My earlier model NG had black rims (with green centres and gold lining), spokes and hubs.
My 48VG has just black. I can't see any evidence of Cadmium or Zinc plated spokes or nipples on the original VG wheels.
I also can't see evidence of gold lining on the VG wheels. They look to be original paint, just black.
When I rebuilt the wheels on the NG, with black rims and spokes, I did leave the new nipples zinc, which I think looks good, but may not be correct. It's hard to tell given this is a part of the bike that is very exposed and if they were plated, they may have been painted later due to rust. It's hard to tell between 60 year old paint and 70 year old paint...
'51,'56 Squares, '48 VH, '27 Model C, R67/2, Mk IV Le Mans, '06 Super Duke and Ariel projects.