Alrighty then.
Got the brakes greased and back together.
The sprocket was no biggie after I ground the dust cover flange off so the sprocket fit over it. I made a wheel stand out of a bucket that helped the process-
The coaster break arm was a biotch, To avoid re-living that nightmare, I'll just say a five pound hammer, vice, and torch took care of that.
The chain tensioner was no fun and a re-education in geometry and dislexia. I got that all done though, just took two hours.
Even though the sprocket ran true with no run out axially or radially, the chain loosens and tightens a bit as the chain goes 'round. I pushed the bike around the yard as fast as I could run and nothing came off. I'll keep an eye on that, might have to re-do the sprocket, even though it seemed fine the first time.