Okay, some updates here:
Went on a 45 minute ride at 50-60mph and it only stuttered once, other than some roughness in warming up. I've been talking to the local mechanic and we're thinking that because replacing the points before fixed the double timing issue (as odd as that seems), it's worth another try. I'm pretty sure one side sometimes fires 10 degrees or so retarded, giving me a ghost image, and it's somehow due to the points and not the camshaft nose or mechanical advance. I ordered new points and condenser, along with pushrod seals, etc.
Here's a new picture of a plug, after the ride instead of after a choked idle:
What do you make of that? The insulator nose is divided near in half black/white. The left side plug is a more normal Brown/Tan. White half faces the exhaust side.
I checked my valves and they were all okay, the LS intake was about a thou loose. Inspected my diaphragms and they looked flawless - no defects, dry spots, holes or tears. I noticed that the plastic hose sections had a buckle where they meet the carb, with the right side's more pronounced, likely enough to cause an air leak. I have some new ones on the way, I wondering if the RS had an air leak, which would maybe explain the difference in plug readings?
EDIT: Also, maybe this is normal, but I noticed some oil in the RS intake tube, which makes sense because the oil recycling tube exits into the right side. Left side is totally dry. I saw a drop at the end of it when I replaced the airfilter last week. Is there a way for the breather to go bad and start shunting more oil to the intake?