I repaired my gauge several years ago and it still works fine. Buy a mechanical temp gauge that has a flexible metal line ( not plastic, under $25 ) put the bulb in a cup of water and freeze it, cut the line a couple feet from the bulb so the splice will be hidden under the dash and find a piece of brass to join the new bulb with the old gauge. Make sure the hole is open in the line when you cut it, slip the two ends into the brass sleeve and solder together or as I did JB weld them together. Test the gauge in boiling water.