Henschel HS 129 B-2 or B-3, and lots of disposable pilots.
Better yet, a whole production line of stringbags that are remote controlled or curtis Jennys. Something cheap that would either make the russians die laughing or maybe soak up a large portion of their air defense missiles. (Even a jenny could carry a 250 pound bomb, after all, and was probably cheaper to build than a modern drone too! Even today if you had the craftsmen you could make up a ton of these things pretty fast. Bolt any engine that would run and had at least 200hp and a Jenny would fly. Only needs to last say, six flights? (meaning built to last that long). Materials would be cheaper than building a comparable drone since there's zero hi tech other than the control interface. Non strategic materials list too. (unless you consider wire and cable strategic).
Best thing to do is swamp their air defense. Which is my beef about sending patriots. A million dollar missile to down a 40,000 dollar iranian drone? I sure HOPE they don't use them for that. Now if you could build a drone for say, 500 bucks that could haul an artillery round (sans propellent, just the warhead) that would be idea. But I'm sure you could make an RC aircraft out of wood and fabric that could motor along for 50 to 100 miles without spending a huge amount, especially if it's unmanned. Use an iphone or something for the main controller or a raspberry Pi or something. I mean, if they shoot it down the warhead will still go off, right? Of course if you really want to get nasty, V1 buzz bombs were cheap to make too. Not all that accurate, but hey, rain enough of them down in the general area and you'd hurt SOMETHING, same with the V2, though the V2 won't qualify as an aircraft, the V1 might as it does have wings! And even a V1 didn't cost a lot to build. But it DID have some range. And accuracy could be improved on the cheap today. Better yet a V1 with a payload, like a Mark 82 or 117 with a GPS kit on it. Get close, lob it out, then either return the V1 or use it and ram something else. All you'd need is a camera and a phone with GPS.
But for WWII aircraft themselves, I'd still go with the HS 129. The B3's had a 75mm cannon (sort of like our C130 in a weird way?). But the B2 was probably the best of the bunch using either the MK 103 30mm cannon or the BK 3.7cm. It might not take out a T60 but the top armor can be go thru like cheese with the A10's guns. With tungsten rounds and enough velocity? Yeah. And unlike the JU87G, the HS129 had plenty of room for additional ammo behind the cockpit.
Now a Mustang wouldn't be a bad bet either, or anything else with a multitude of Browning .50's on it. Or just buy up a ton of old cessna 172's and put bomb racks on them. You can get a 172 or a 152 pretty cheap and the useful load would put at least a 250 pound bomb on centerline. (or hang bombs off a cruise missile?) Either way, you'd need something cheap, rugged and that would run on the fuel available in UA right now. That pretty much nixes any allied fighter since the minimum was 110 and mustangs ran 150 octane fuel. At least the germans only needed 92 or so.
I would DEARLY LOVE, however, watching via video when a squadron of stringbags attacks the Black sea fleet in harbor at Sebestopol. say, 50 old swordfish with torpedos? I doubt they have that many ready AA missiles to fire. But the looks on their faces would really be priceless!
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