Quick update to close this thread - I did pull out the distributor and replaced the impulse coil. Not a difficult job I was glad to see there's really only one to put it all back together so it's hard to mess it up. I dropped the distributor back in after rotating the rotor CCW about 15 degrees from my mark and when it fell in, the rotor snapped right into place. I got the rest of the engine built back up and when I started the car cold, put my timing light on it and found I was at about 20 deg instead of 13 deg. I was able to "easily" access the 11mm distributor nut by removing the oil filler cap and the vacuum hoses around it, a couple quick turns and checks with the light and now I'm timed perfectly once again.