Belated (past-two) weekend update:

New master cylinder and new right rear wheel cylinder (pedal feels much better now)
Removed front hubs/drums to confirm those wheels cylinders are okay - repacked bearings.
R&R right rear wheel bearing and install NOS right rear axle half-shaft. (Empirically confirmed that there truly is a difference between front wheel studs and rear wheel studs, so some "re-work" in this process)
Polished bearing surface on existing left rear axle half shaft.
Cleaned magnets in the pumpkin and re-filled with fresh gear oil.
As an aside, I verified my entire family's olifactory objection to gear oil!

Bill

1947 3100 Advanced Design

Never, never, never, never give up. - Churchill