Just to clarify one thing, Edwards AFB still has a lot of those highly-skilled engineers. Edwards has a huge machine shop with all the fancy tools and the engineers in there job is mostly making one-off replacement parts for planes. NASA and the Air Force are still flying all sorts of test planes out there and they often need some part they can no longer get from the manufacturer. They drop the spec for the part and it gets made, sometimes it takes a long time, but I promise there are skilled people on that base who can make it.
IMHO the SR-71 is going to be problematic due to sourcing the materials and fluids more than finding skilled CNC techs.
source: worked on Edwards for several years