Prototypes for Con-Cor 40' Box SD and MRC/Con-Cor 50' Box PD

[Spikre]

 
  not sure what Proto the Flat was based on,but from the 20s to the mid 40s there
  were a number of 46' and 48' flats constructed.
  Gondolas were also built in 46' and 48' lengths,but some were Mill gons,and others
  were Hi or Low side GS gons,some with drop doors,some with solid floors.
  interesting how close the boxcar came,then lost it with the roof and odd end ladders.
      Spikre
       

[nkalanaga]

Many of the GN's boxcars were home rebuilds, which resulted in a few oddities.  I wonder if this was based on someone's 1:1 kitbash?  It looks like an old car that was modernized, possibly with all-new sides, in the early 60s.