The bed dimensions given at about 45 1/2” x 77 1/8” seem to indicate the bed might be from a ‘37 or ‘38 half ton. Those dimensions match more closely those shown in the 1937 Specifications reference shown in the attached photo. As I understand it ‘38 specifications would be the same as ‘37. Photos attached also show dimensions shown in the ‘46 Specifications, which would be the same for ‘41-‘46. I don’t have speciations books info for the ‘39 and ‘40 models. I’m uncertain from my interpretation of the Master Parts Catalogs of the possible continuity from ‘39-‘46?
Hope this helps and if I am incorrect someone hopefully will offer corrections.
