good question. When I figure it out... Same tool. Same rotating...That looks like success to me!
Nice knurl on the grip edge.
I notice one is left and one is right.......did you do them in different orientations, or will different tools?
I had the gears, just hadn't used the threading dial I had installed before. Opposing odd numbers worked great. Even figured out how to remove the work piece from the chuck, put it back in the chuck and align the threads to continue cutting11 1/2 is a common NPT lead, every inch lathe ever made will have gearing for this,. The NPT standard was developed in 1864, I suspect that your machine is not older then that (-: