'37 barn find,
Lubriplate makes the exact oil you are looking for, their SPO-288. I found it available in quarts at WBC Industrial in Colorado Springs and I've been using it for many years in my '36 Chevy pickup that I've had since 1965. With the Lubriplate product the '36 transmission shifts much better than it did with any parts store gear oil and better than with so called "600W" oil offered by so many vendors. Interestingly that "600W" stuff isn't even gear oil. It's steam cylinder oil.
Ray W
