An alternative viewpoint:
Stock is a lot easier to do than modified. Most parts are readily available through catalogs and they are, by design, direct replacements for original parts. Modified cars and trucks take a lot more fabrication, although many parts are being made for specific applications. Many rodders buy someone's restored classic as a base from which to start. Stock isnt worth as much as custom, yet it still costs a bundle to do. Most folks here are of a like mind - mild customize / modernize. Driving the secondary roads in a stock truck gets old fast when there's 10 cars behind you and no place to pass.
Unless I'm mistaken the old knee action shocks are only single action so an upgrade to tube style shocks will be an upgrade to safety. You dont have to have disc brakes to be safe but they can always help. I think the dual master cylinder is a good idea regardless.
The truth is that none of these trucks are rare. You found yours after looking around for a short while just like the next guy will. I suppose that every once in a while someone actually takes one back to completely stock from a modified state but it musn't be common. I suspect most restorations are approached from a good solid original example or a neglected state but hardly from a rodded state.
I could be wrong.
The world is full of 50+ year old trucks that barely run 50 mph and can't drive straight. Be daring and build one that can run safely at 75+ all day long with A/C blowing and 20+ mpg.

That ought to get some folks going...

hehehe


Gravity - It's not just a good idea, it's the law.