12 minutes ago, Yarb said:

No need for a tube bender if you’re not set on authenticity. Install a couple of flex lines.

ah, cool. ok, that's the plan.

I took it apart one more time, and almost got it working. I replaced the new seals with the original ones (which probably weren't original, but age unknown). This allowed it to actually start working, and I could hear shoes clapping into place, but it revealed another problem which had been hiding in there: the long stop bolt (hole) was stripped out. Probably by me, but I can't say. So that was also leaking.

On the plus side, I am now really good at bleeding MBCs and wheels in a relatively mess-free and fast way.

Well, that took a lot longer than I thought, but alls well that ends well.

I got a new MC from ZCar Depot (the cheaper of the 2 7/8th options). This one has reversed reservoirs from the one that came with my car, but flex lines from California Datsun worked great. Did bench bleeding, installed, bled the corners... brakes kinda work, but not really. tighten up rear wheel cylinders, do the whole thing over again (tried different angles when bench bleeding, for example). Checked for reaction disk having fallen. tried adjusting the setup with the pedal. everything I could think of, but still only felt solid when pedal is already half way down.

Probably everyone knows by this time what it was, but it took me a long time to think of it. the MC that came with the car basically had the piston cup right up against the end of the cylinder where it fits into the booster. The new one, upon removal and examination, sits about 1.1-1.2 cm further inside the cylinder. so the pushrod wasn't even contacting it until the brake was half way down. Took out the pushrod, extended it (seemed to be pretty extendable, but a little worried I didn't keep unscrewing until I knew how long it was in there. felt solid anyway). et voila! brakes are firm. Went for first "joyride" in 8-9 years. all of 3 blocks away before I turned around and came back. the shock bump stops crumbled to dust and I'm still waiting on new struts from MSA. Don't want to hit any bumps too hard.

Now for a nice water free wash.