I can’t tell from the 3rd picture too well, but it looks like some kind of stud at the end by the column. A correct lever is installed through the slot as pictured and then secured with a specialty, long bolt through the hole in the switch into the lever. Is that a Daniel Stern repro turn signal switch? If so, it’s an exact reproduction on the original - great switch!
I emailed Dan via his website, but did receive a response. I know he has somewhat dropped off of the forums so I purchased the next closest repro I could find. Is there an additional cam cancel plastic piece that I am missing?