I just read through the entire thread, great work.
I am at the beginning stages of a similar project started with a 49 (maybe 50) 3600 and planning a SBC engine (383) with an NV3500 transmission. The NV3500 has a hydraulic slave but I have not decided on the master/pedal arrangement yet. It looks like you may have mounted your master under the floor near the brake master but any insight you could provide on that would be greatly appreciated.
Somewhere in your thread there was a comment about converting to power steering and then being able to use rams horn exhaust manifolds. I wish I could recall who made the comment but I would appreciate any additional information regarding that approach.