Well I am still confused..
On the side that was locking up (starboard) I cleaned up the grease (without disassembling the brakes), did a partial bearing repack (they only had about 3100 miles) and replaced the seal. Then re-adjusted the brakes and did a parking lot test.
The starboard side still locked up (or at least locked up before the port side), so I backed off two more clicks on the starwheel. From the point where I could not turn the wheel with one hand, the starboard side starwheel was backed off 8 clicks and the port side 6 clicks.
Did another test drive and was still getting wheel lock-up at anything close to the setting I had been using without lock-up since picking up the camper (10 volts max). I backed it down and went back and forth on the setting while doing stops from around 15 MPH. I finally settled on 6.2 volts and then hit the road. At this setting the braking seems good from slow speed as well as about 45 MPH. The wheel is not locking up unless maybe I really hit the brakes hard. The starboard side does run hotter. Probably not too hot in normal use but after all my repeated braking for testing and adjusting, the right drum was too hot to hold my finger on but not the left.
So at this point I am wondering if there were two issues:
1. The obvious grease leak
2. And perhaps in fact the brakes were not adjusted right from the start, and I was using a higher controller setting to compensate. Is ~6 volts a reasonable max setting?
I feel good enough about it to head out in the next week and do about 120 miles on secondary highways so we will see how it goes.
PS. My photo has a hidden watermark and copyright