1968 Dart gauge help

After reading your reply Mattax I went out to retest the gauge and came up with this. Is this gauge still usable as I do not think I was testing it right before? I had to add the larger bolts because the the studs are kind of loose when I tried to test it again. Should the studs be wobbly or tight in their fittings without the retaining bolts that obviously will firm them up after installation. Also the fusible link I believe is from a later year car because the harness connector is different. I think it was changed out prior to me owning the car. I think that shouldn't be to much for concern as I think the links are the same except for the harness ends. Thanks for your time Mattax!

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