John, went out and measured-spacing is 6". On the inside of the left hand cover is the words"Capacity" and "Bushel per foot"painted in 6" yellow letters. 
The only way that I know that this is a model 38 is by the Sowing chart. On top it says Model 38 Drill 6"--7"--8" spacings. How many transmissions did the one you looked at have? Mine it ground lift, not hydraulic. How about that one?