Actually, re wiring, I offered that as a typical red-herring argument offered by heritage opponents, i.e. "with designations, you can't do nuthin' without jumping hundreds of hurdles or offending someone". Not as *my own* opinion--though of course, with designations you have to be careful *how* you do it (at least as regards street frontages)
And re concrete: this was largely cast in place, too. And yet it was demolished on, er, safety et al grounds.
http://www.archdaily.com/86743/ad-classics-orange-county-government-center-paul-rudolph
And if you think that was the proper thing to do, well, grievous heritage fail on your part.
Look: *technical* resolution is not my expertise--what I'm offering is a differing, more overarching form of "resolution", which is fueled by a different attitude towards the architecture in question. Like, let's go back to this quote of yours...
Okay. With the "recreate which isn't preservation" part, you're presenting a ultra-purist cartoon of preservationism; like, it *only* has to be original materials and elements, or *only* installed according to original (and as we now know, faulty or limited-lifespan) specifications. (And like the knob-and-tube red herring, it's a detractor's cartoon.) Look, if things went that far in the ultra-purist direction, that which is Victorian or Deco would be technically no less (and maybe in some instances even more) economically prohibitive, as you'd have to procure trained, specialized craftspersons of all sorts to make things ohsoperfect. (And *keep* things ohsoperfect, given how a lot of these edifices have had to be re-scaffolded and re-restored and fine-tuned at inconvenient intervals.)
In fact, the probable nub of the problem is the "something that isn't too popular" part. So, may I ask, "something that isn't too popular" with...*whom*? *You*? Well, as far as I'm considered, that's your problem. And other than that, whom? The sort of people who think the NPS walkways are a view-blocking eyesore that would've been better off torn down? You really want to pander to *that* mentality?
In reality, I don't think it's a matter of "non-popularity", so much as a matter of casual, everyday non-engagement--something which, unlike non-popularity, *isn't* necessarily founded upon inflexible hostility. The silent majority that *wouldn't* view a 60s precast wall restoration with a "why did they bother with this dated concrete crap which'll fall apart all over again" axe to grind--and in fact, quite a few of them might even be intrigued and drawn in by the whole process, Doors Open-style. And that, in the end, might wind up its own best economic argument: a historically conscious self-appreciation, inviting others to join in...