Just a temperature switch. looks like it is set to close the circuit at 150 degrees. Somebody came up with a custom temp alarm is my guess. I like the ingenuity.
The corvette kits work well, amazing the difference. I always end up fiddling a bit to get the centering adjustment correct. Lube definitely helps on the ball stud.
New steering systems don't really cost much and with age, they probably could use a refresh also. and eliminate the NLA cable issue plus get that like new feeling from the steering.
https://www.mrcool.us/fresh-water-cooling-kits.html Give these guys a call, I installed one of there kits on a similar vintage 350. They have great customer service.
