How about a B-52 and a Tu-95? Both available in 1/144th if you don't want to break the bank/marriage.
Surely the natural swaps for a Buccaneer would be either an A-6 Intruder (RN/USN markings) or an F-105 (RAF/USAF markings)?
How about a three-way (ooh-err
) between an F-111, a Tornado and an Su-24 Fencer? F-111 in Soviet markings, Fencer in RAF/Luftwaffe/Italian markings, and Fencer in USAF markings.
EE Lightning and an Su-7? Both extreme-sweep designs, and the Su-7 was originally intended as a fighter before it was moved to the attack role, so maybe put it in an NMF scheme and give it some AA-1 Alkalis? Alternatively, use a Mig-21, Su-9 or Su-11. You could even put Firestreaks on the Su and Alkalis on the Lightning: the latter are short, so they'd probably fit on the Lightning's inboard wing, ahead of the undercarriage bay on the original Russian pylons. To confuse matter even further, you could put a pair the distinctively Russian MiG-21 drop tanks on the Lightning's overwing pylons...
Vautour and a Yak-25/27/28?
Mirage 2000 and an F-16?
Curtiss P-40 or Vought Corsair swapped with a Dewoitine D.520? Both designs with the cockpit relatively far back.
Mitsubishi J2M Raiden and a razorback P-47 Thunderbolt: both big, beefy radial-engined designs.
Gloster Gladiator and Polikarpov I-153 or I-152?
Gloster Gladiator and PZL P.11c or, better yet P.24 (enclosed cockpit GR-engined export version)
The Avro Shackleton and the Lockheed Neptune could be swapped over as evaluation aircraft, so could the Lockheed P-3 Orion and the Breguet Br.1150 Atlantic.
The RAF actually flew Neptunes though, so it wouldn't look out of place in UK markings. The P-3/Atlantic swap sounds good though: they're in different size/range categories, so you might imagine the USN taking on the Atlantic as a natural replacement for the Neptune, in exchange for the French taking the Orion as a long-range complement to the Atlantic.
