[Ross in East Texas]

I just used Tin/Lead acid core solder. I bead blasted the steel and sanded the brass for a good surface to "tin" and flowed the solder on the hot surface to get a decent fillet of solder. I did have to swage the brass tubing slightly larger to fit into the original hole in the cover. This allowed me to insert the brass tubing so it would maintain position. I squared the tubing in the cover on my lathe prior to soldering so the tubing would not be off center in the steering shaft.
I did use emery cloth on the switch rod so it would fit slightly looser through the brass tubing. My rod had some minor dings it seemed.