I have a small list of verified users of the 6' wide Youngstown post-war steel 6/6/5 door. Ted Culotta has a UP B-50-39 40' 6" ACR HO boxcar resin kit which (witch) uses Dan Hall's accurate door. I have some additions:

Great Northern 40'-0" IL 8 panel plywood sided boxcar # series 10800-10899, the last 100 single door plywood boxcars built new by the GN in 1947. These are the only cars I have found where a nominally 10-6 IH door was used on a 10-0 IH car, a practice GN often followed.

Gulf Mobile & Ohio 40'-6" IL 10 panel riveted single door 10'-6" IH boxcar # series 21000-22419 with 1419 cars listed within the group in 1953, built in 1947.

Nashville Chattanooga & St. Louis 40'-6" IL single door 10 panel riveted steel boxcar # series 19000-19499 with R+3/4 IDE, built in 1947.

Norfolk Southern (original) 40'-6" IL single door 10 panel riveted steel boxcar # series 27000-27249 class XM5 with 4/4 IDE, built in 1947

Union Pacific 40'6" IL 10 panel ACR riveted steel single door boxcar, series 197000-198999 class B-50-39 built in 1947.

I have photo documentation for all of the above acquired from the Gerstley late 50's color slide collection. I have just screened the the "G" through "N", so hopefully, I will find other examples. Feel free to add to this list. Thanks,
-Andy Carlson
Ojai CA