Hey Gary - Thanks for all of your contributions to this thread!
I have taken recent interest in this because after reading this entire thread, I began taking another close look at my father's Cman tools. I had always suspected that the majority were purchased in the 60s, specifically mid-60s around the time he graduated from high school. With the information here, I was able to confirm that suspicion.
With the link to the catalogs, I now suspect my father purchased the 138-piece tools set on page 3 out of the 1964 catalog. (set 99 M 43394K) I'd always assumed had purchased the tools seperately but after seeing what was included in the set, he had
every single piece correctly dated except for:
1/2" ratchet (stopped ratcheting and I warrantied it 11 years ago)
3/8" drive, 3/8" deep socket (I broke this, surprisingly thin walled, warrantied it 11 years ago)
3 pc punch set (sold by accident at my garage sale, have photo evidence sale table beforehand

)
4" flat blade (sold by accident at my garage sale, have photo evidence of the sale table beforehand

)
Finally, the only piece that I suspect was actually missing not do to my stupidity was the 3/8" crossbar.
I have been posting in the classfieds and Rickster here had sourced the socket, ratchet and punch set for me with the correct series codes, without part numbers.
If you (or anyone) can help lay my hands on the 4" screwdriver and the crossbar, I would greatly appreciate the opportunity to re-complete my father's tools. I find it interesting the crossbars don't have any markings at all, you wouldn't even know they are Cman. If anyone has the proper 3/8" crossbar but doesn't want to sell, I could really use the overall length and diameter of the bar to use in my search
Here are some pictures of the tools that I used in my 'want to buy' adds to contribute to the thread:
4" version of these flat head screwdrivers, G - no circle
2pc Chisel Set (G circle):
Finally, the 3/8" drive crossbar that matches these (1/4" drive and 1/2" drive shown), no markings
Here is the set:
My father bought this box instead of the Cman, which is VERY well built and reminds me of the Snap-On boxes from the era.
I was lucky to run into a garagejournal member that was selling this so I bought it. I've never seen another set like this. The set is united and looks awesome together.
=V= socket pics, like I said, very thin walled:
The screwdriver has G without a circle. I think we can agree that this wasn't made by Easco during the years stated. Should have this been stamped G-circle?
The chisels are stamped G-circle. This supports your notation on G-circle that it ran until at least 1964.