I realized I needed a front brake on Ratty. The rear brake alone doesn't quite inspire confidence when needing to stop at 50mph, which didn't think I would be running that fast in this beast. I'll let the pictures and captions do the talking.
Old grungy front brake inner workings:
Backing plate, two shoes, springs, and the rotating shoe spreader thingy:
All cleaned up, pivot points lubed:
Shoes and springs installed:
I had a spare front brake cable that I made work after some fiddling and head scratching. I haven't yet run the bike out on the road, but it does stop the front wheel from turning when applied!