I'm trying to determine the location of the retainer valve on the B-
end of Great Northern USRA double-sheathed boxcars, series 23494-
24993. I'm modeling a car circa 1948, with a vertical brakewheel and
Photos of other USRA double-sheathed boxcars show the valve as being
located to the right of the brakestaff, just above the top most rib.
Did the GN cars have the same arrangement?