I'm guessing they would have had B/C models and then the D's.
For a D in 1/72...Airfix. Having done Academy, Heller, Tamiya and several Airfix 51's...Airfix will get my vote every time. They even have one boxed with RedTails markings, and it's 1/2 the cost of the Tamiya 51 (if even that much!)
For a B/C...the Academy kit is nice...much better than their D.