Truthfully, the A-10 Thunderbolt II design is good for another 20-30 years, and those parts that need upgrading, mostly electronics, tend to be modular. So why not contract with a friendly foreign aircraft manufacturer to make an armada of them, but with empty holes for the electronics?
The hardest part to get used to be the engine, but there are now several quality engine makers.
I have a few years working on the Hogs. Never got to see them in action but they did a SAR demo at Osan that felt like the real thing. The 16s did top cover and the 10s did the dirty work down low. The 16s had a good loiter time but no weps only flares.