Re: RPO Paint scheme question

Kevin,
The ends were treated with fire retardant material that was really thick, ugly, and it was just gooped on over everything.
That it was probably black when it was applied wouldn't surprise me at all, and it looked like it was black under the flaking gray paint as they sat in the Durango Yard years ago. But I think Fred is probably correct, as the cars were painted, there would have been no need to mask off the ends to leave them black.
The fire retardant material was just one of the innumerable features to RPO's used on American Railroads that was required by the US Postal Service for compliance to be able to handle mail under their contract.