I have a like new Studebaker radiator temperature gauge, the kind that
screws onto the radiator in place of the radiator cap, like the old
antique cars used to have.Yep, I bought it years and years ago at one of
the Goodwill stores around here.
http://www.shopgoodwill.com

Those kinds of old style reproduction radiator temperature gauges are
still available, if you know where to look for them.Studebakers, Fords,
Chevys, Chryslers,,, you name it.
cuhulin