Dan-



You don't need a casting number to spot a '39 shift cover. It is easy to check and it only takes a second.



The '39 requires a different shifting top (I am not talking about the lever) than a pre-'39. There are a couple of reasons for this but I won't clutter your mind with them, just look on the left-hand side of the shift cover and you will see a screw. On pre-'39s the screw is 1/2" across. On '39s the screw is 5/8" across. If this sounds confusing let me know and I will send you a couple of pictures showing what I am taking about.



Hope this helps.



Tom