Made some progress on the brake system. It's more complicated than I would like but given the space restrictions, not a lot of choices.
Installed a remote hydroboost master cylinder from Vanco in CA. It is actuated by a little 3/4" clutch master (that's all there was room for in the engine bay). Had to fab and install a large bracket to hang it on the fishplate and still need to plumb the whole system but at least making some significant progress. Will get back on the engine seriously in a couple of weeks.