I've had my sender in and out 3 times. Still reads low. Do you have one of those "hit it with a hammer, screw removers"? If you don't, I can loan you mine. I had to use it to get the old phillips screws out.
It looks amazing by the way. It will be fun to get our land cruisers together.
The terminal size is based off the width of the male. I know .3inches or 7.8mm is the next size up from the standard 1/4 inch. Can you get to the mate and measure it?
Not sure if you've ever had a car or truck repainted. It is a special joy that is specific to gear heads. There isn't much in this world that is as exciting as watching something become new again. Congratulations.