Tim, I'm not sure what this tool is. Initially I thought it was aluminum but now do not think so.
What got me thinking about this is a post by spin132. He has a very nice, early Combat Magnum. He picked up the Blued steel knurled-handled SAT for his gun.
SCSW says:
Blued steel knurled-handled screwdriver 1940-1958.
Aluminum knurled-handled screwdriver 1958-1961.
In post #27 John says K260006 was shipped with an aluminum SAT and that would have been in 1956, so SCSW is not completely correct.
This tool is heavy and sticks to a magnet. I think it is nickeled steel and not aluminum. So maybe Nickel knurled-handled screwdriver 1940-1948.
I don't really care if it is the correct tool, just trying to learn. A rare and valuable item whichever it turns out to be. Think I will take it to Tulsa and let the experts have a look at it.