When you say " powder finsh" do you powder coat? It that "100% correct in every way"?....... Mark
Not exactly certain how to answer your question...
Do I use the same exact materials Ford did to finish (paint, plate, etc.) individual pieces? The answer to that is "no".
The products available today are far superior to what was available in 1940.
Do I accurately recreate the colors authentically used? Yep, sure do.
I go to extreme lengths to be certain every nut, bolt, washer, etc. is what Ford used when the vehicle I am restoring rolled off the assembly line.
I am also aware that my restorations are not "exact" by definition. Why? I seek and demand from myself as close to "perfection" as I am able to achieve. That being the case, the vehicles I restore are well beyond what any manufacturer offered then and well, even now.
Examples: While I have the luxury of making the frame flawlessly straight and beautifully finished, Ford did not. Do the doors, hood, etc. align perfectly? Yes, they do. From the assembly line? Typically they did not.
So, in those respects, my restoration is not "exact".
I hope this answers your question...