Prop spray paint. Help!

[nacelle]

I am making a replica mobile holo emitter but i cannot find the right paint for it.
I either need Duplicolor GM478 Med. Marblehead Metallic or Plastikote 7173 which apparently doesnt exist anymore.
Can anyone suggest an alternative to either of the above that i can get in the UK?
The above both seem to be GM car paint which is not in the uk anyway.
Halfords does 73 different colour silvers for various makes of cars. I wouldnt have a clue which one would come close.
Would be very grateful for a suggestion.
Thanks

 

[Rattrap]

Don't know if this will help, but here's a US source for the paint. Maybe they can help you find a source, or send you a sample card. http://www.brandsport.com/dupl-bgm0478.html

 

[nacelle]

Thanks but if its US then its no good. They cant send spray paints air mail. I only have couple of weeks left to make this and i have googled these paints to death.