C30-7 ATSF Locotrol Box

I am superdetailing five Atlas C30-7s for the BNSF. When completed they will be operated as a consist (DCC) pulling a unit coal train of an, as yet, undetermined number of cars. One of the units is BNSF 5176 which is being modeled in the SPSF “Kodachrome” livery with a BNSF patch. I have located all of the “after market” detail parts with the exception of a Locotrol box (mounted aft of the cab) that I will need to scratch-build. If necessary, I can derive the dimensions from various pictures. However if someone can provide the dimensions that would be a great help.

Respectfully,
Jerry L. Lentner