Classic/Antique Car Repair: 600W Oil

Question
In one of the Model A catalogs, listed is 140 SAE Industrial gear lube. Is this product is the accepted oil for the old 600W oil in the transmission and steering?

Answer
I don't know. We all still use the 600wt we get from the catalogs. It probably is ok to use if a model a supplier is selling it for that purpose. I have heard of a heavy gear oil, but it was harder to get than the 600 wt.  I use stp in my strg gear. A little thicker and takes longer to leak out. Some people mix it with 600.
I don't think the A transmission cares what is in there, as long as the level is kept up.  Sorry I can't be of more help.  Be sure to drive your car a lot. That's the best thing you can do for it. Take it for coffee every day or so.  Jack