K-Line Aluminum Passenger Car Finish?

I've noticed the same thing, but they came from the factory that way - it was a change design production or maybe they switched factory/contractors at some point. It might be possible to "frost" the shiny ones or polish the dull, but I wouldn

't try if they were mine. 

Jason...I own a bunch of these cars and found that there were several runs of some of the road names throughout their history.  The early runs of the ATSF cars were in fact lightly painted to dull them down.  The last run of the same ATSF cars were unpainted and highly polished.  This led me to put together two separate ATSF trains with matching cars...even though some of the cars have the same name and/or road number.

Alan

You fellows really know how to hurt a guy....

Two trains worth, and here I was happy to have one good one. 

Thank you both very helpful I do appreciate the help.

I have one Zephyr car, and it appears to have been plated.  I prefer the natural aluminum.  I believe Lionel used an anodized finish.  GGD is painting them.  Most of mine are Mac Shops, and simply polished.