Final update time. I got it all together, and it started just fine, idles and revs up without any oil smoke and no bad noises. I rode it around the block, no problems. Then I rode it in a longer loop I use in my neighborhood, and over 40 mph it cuts out and sputters terrible, but below that it's fine? WTF? I took the carb out, rechecked the jets (all clean), reset the float level, examined all the vacuum lines, and checked the fuel petcock. All normal. The battery is good and strong, almost 13V, and the reading goes well over 14 when the engine is racing. The spark plug is new, the wire is tight and solid. So, WTF?
Two days of screwing around, and nothing helps. So I start reviewing everything I did when I replaced the piston, because it ran OK before I did that job. And, after the required head slap, I knew I put the cam chain on one tooth off. Every time the spark advance circuit kicked in the intake valve wasn't closed yet when the plug fired. I just got that straightened out, and it runs great.
The DMV visit yesterday was confusing, but after 2 hours it looks like I am going to get a title. We'll see. They got my money.