I've worked on a lot of the parts for that program... funny thing is that there is no way anyone held the tolerances that were on the prints back in the day when the planes were new... fast forward to now and we can make them to print and now the parts don't fit as they're way to tight. Have had to work through getting variances accepted and I know guys like yourself have had to "manipulate" some of them to make them work! LOL!
Where are you at?
I've worked with a few older engineers in the past and from their stories, the A-10 wasn't built from prints, prints came after the fact as a government requirement for purchase. The story goes that it all started with a large hangar and a plumb bob where a mock up of the left side was built. From there master tooling was built per the mock-up and reversed to create the tooling for the right side tooling. From the master tooling they developed master parts to be used as the baseline for all future production parts. You can tell a master part as they were painted red and stenciled with a P/N and other markings.
I've been lucky enough to work with a few of the assembly fixtures, bond forms, and held actual master parts. You are correct, most parts have to be reversed engineered from a combination of loft, actual parts, prints and tooling. We have yet been able to manufacture an actual part from the drawing that accurately matches the original tooling or fits an aircraft. Lots of tweaking involved.