Your biggest problem with the A-1 Sky raider would be the R-3350 radial engines. Other than a few air racers I doubt you’d find any parts.
This is why they are pushing the Embraer Super-Toccano and it’s turbo-prop engine.
A radial engine is not a difficult thing to manufacture. Of course, it might have a tough time passing EPA regs, so would be rejected.
OK, but that radial engine sound can really inspire that last minute freeze in the open and crap-in-your-pants moment when they know they're going to die.
Super Tucano. Two .50 cal machine guns and 3300 lbs on 5 hardpoints. 800 mile range.
Skyraider. Four 20mm cannons, 8000 pounds on 15 hardpoints, 1300 mile range.
Not even close to a substitute.
And for extra fun, the good ol’ Warthog. A 30mm gun from hell, 16,000 lbs on 11 hardpoints, and super long legs and loiter. With refueling, it can get ridiculous.
The obvious conclusion, the government does not care about effective CAS.
If you can re-engine a DC-3 or a Bonanza or a Cessna 210 to a turboprop, you ought to be able to convert an A-1. The original engine was about 2700 horsepower with a weight of just under 2700 pounds. A T-56 weighs 1940 pounds and produces 4300 horsepower. Even with a re-designed nose and some extra fuel, it should have more power for the weight and be able to overcome any loss of aerodynamics caused by the conversion. Slap on a modern 6 or 8 bladed prop while you are at it. And some extra armor.