Again, if there truly were no voltage (relative to ground) at the dark green/light green wire of all the coils, there is no way the engine would be running a-tall because the coils would have no electrical power. Make sure your meter leads are making good metal-to-metal contact.
Often, the electrical connections on these old cars have surface corrosion that may look like you can get good electrical contact just by pressing the meter lead tips to the metal, but there is an invisible corrosion that is insulating the metal from good contact with the meter lead tip. This can be especially true of body/frame/chassis parts that you are trying to use as ground point (because they are so exposed to the elements).
To test what I am speaking of there, put the meter in resistance (ohms) mode, and touch both leads to the same piece of metal but not touching each other. If there is that insulating surface corrosion that I was talking about, you will get high ohms reading (typically several mega-ohms, or "Over Range" indication). If both leads are making good contact, you should be reading less than 1 ohm.
I've seen it where you can press really hard with a pointed tip where it appears to be digging into the metal, and all you're doing is indenting the metal under the corrosion without busting thru the corrosion, and damaging the lead tip in the process - you might see the meter start to shift into a lower ohms reading, but only briefly as you wiggle the probe around. You might need to burnish down to the metal with crocus cloth/sandpaper/emory cloth. After doing that, test that area with the two leads in ohms mode again - then make your measurement. (Don't forget to put the meter back into volts mode before putting the leads across voltage!!)
A tip: You might want to go by Radio Shack and pick up a pack of jumpers (several in a pack for a few dollars) with alligator clips on both ends. That way, if you want one meter lead on one point (such as ground) while you move the other lead around to different other points (for voltage readings or whatever), you can focus all of your attention on placing the second lead where you need it for each measurement. (You can also get meter leads with alligator clips, but the jumpers work just as well and give you more versatility, and for less money.)
Radio Shack jumpers to consider (the larger ones would be better for connecting a meter lead to a convenient ground point):
(ten small 30" long - $7.99 cat. no 278-1156)
(eight small 24" long - $6.99 cat. no 278-1157)
(four large 30" long - $7.99 cat. no. 278-001