The thermo-time one is the one with a tab on it so the plug goes on the right way (it might be cracked with age) See: http://img.eautopartscatalog.com/live/C401012256VDO.JPG

The water temp sensor has a female plug end. See: http://img.eautopartscatalog.com/live/C602012894BOS.JPG
The 2nd one is the one you want to check resistance on. Make sure it's within a reasonable range of what I posted. If your engine is cold and it's reading 0 ohms (short), replace it. If your engine is hot and it's reading 1 kohm (way too high), replace it. These USUALLY don't fail. I'd suspect a vacuum leak or malfunctioning thermo-time switch before this.

You say it hasn't been run for a while. Clean the points (if you didn't replace them). Regap if needed. Set the timing to 5° ATDC with the vac line connected to the distributor - if there is no vac at this line, plug it for the time being and set your timing to 7° BTDC. Take it out and RUN THE CRAP OUT OF IT. For every time you floor it on the highway, kicking it into 2nd gear at 75-80MPH, you will blow more crud out of the engine.