Caboose window plating over

[nw-mailing-list at nwhs.org]

Hello
        I am wondering when the NW began plating over some of the windows on 
cabooses.   I have the big red caboose book by the NWHS, and I'm getting the 
impression it started around 1978.  Would that be right?
 Were the cabooses mostly worked on  in one shop or was work done on them 
around the country ?
  Any info is appreciated,  Ken Rees