Hot Line only has one bell that rings for the 10s, 100s and 1000s. No bell for the 1s. You just hear the 1 point relay clacking away. Interesting that they did that for a game that has all those 1 point rollover buttons. It's been said that it sounds like a popcorn machine and that is so true.

You can buy the bell and the knocker assembly whole from Pinball Resource. You don't even have to worry about the coil since the Gottlieb coil coming with the assembly is 25v and Hot Line is a 25v game.

A coil that is under 3 ohms is not a dead short. Most pop bumper coils are under that. It's once you get near 1 ohm that you get into that area. I know you didn't say this, it was said above you, but I'd agree with Alex, that doesn't look like a smoked coil. They really only go bad if they lock on and burn up and the wrapper will let you know it's gotten hot. Disassemble that and put in a new sleeve and get a plunger and it should be ready to go. Clean up the jones plug too.