Retooling it is not that big of a challenge today. Knowing the power of reverse engineering, as it is something I professionally do, the modern tools of laser 3D scanning in as little as .002” tolerance is something already there. Converting those laser scanned parts into 3D CAD for the generation, not only of the parts, but also for the generation of new tooling die machine files is also part of the advanced package I use, SolidWorks Premium, but also for its big brother Catia which is widely used by the auto manufacturers. Unless drawings are available, the only thing that requires any destructive analysis would be for any grain matrix of the old parts, if one was specified.
I would wager that is how Boeing will be producing the new wings. I know that one of the Fairchild companies is still in existence, under a different name, that has the same capabilities to reverse engineer and has been using it for quite some time. It is located in Crestview, FL.
I am a huge advocate of reverse engineering the Warthog, updating all of its avionics and control systems, and at it make it even more resilient to ground attack than it already is.
Boeing is already producing the new wings - they didn’t bother retooling, just designed a new set. It was cheaper. http://www.boeing.com/defense/support/a-10-wing-replacement-program/index.page
Keep in mind that we don’t have any new, untouched Warthog parts to scan in any more - all the airframe parts save the new wings are well used and abused and therefore would not be quite true to original spec.
The original plans, specs and blueprints were also all destroyed with the tooling by order of Congress.