Actually, in 1946 I'd be very surprised to see a boxcar built new with a wood platform. I can clearly see the serrated edges and crossbars typical of an Apex brake step. The running board is also Apex.

Of course, if you don't believe me, you can go to the tables of Postwar AAR boxcar information located at www.steamerafreightcars.com, and click the link for the Postwar AAR cars with 4/4 ends. Ed Hawkins has already answered your questions, with the exception of whether or not the roof was painted. And I don't know the answer to that one. 

People forget about the Steam Era Freight Cars site, and the wonderful information stored there. Ed Hawkins has answered most questions anyone could have about specialties for the 1932 ARA, 1937 AAR, 1942 AAR, Postwar AAR, and PS-1 boxcars.

Regards,

Bob Heninger

Minot, ND