If I were you I'd check out Krylon's satin Nickel spray paint in their 'Brushed Metallic' line...
http://www.krylon.com/products/brushed_metallic/
I've used it several times when I'm seeking a more 'steely' or stainless steel appearance than the more common silvers and aluminums give. IMHO, they're too garish to represent any of the steels.
That said, when I restore one of Lionel's 2500-series passenger cars, I repaint the plastic vestibule moldings...and sometimes the truck sideframes, if I'm so inclined...with Tamiya's Silver Leaf spray paint. I like it for two reasons: It has the best quality spray pattern/coverage of any of the hobby rattle-cans (IMHO, of course). Also, the color is very uniform and consistent, and it's a very good complement to the 'brushed' silver of that series aluminum car shells.
FWIW, always...
KD