In resin, I think.
Mach 2 did a combo kit of the A&B, in 1/72. Will PM who has a couple. Around $35.
PM window won’t open. Rebelalpha on eBay. Have bought from him numerous times, great guy to deal with. Never an issue with him or his items.
100% agree on rebelalpha - solid dude.
Fantastic Plastic.com has them in resin in 1/48.
Vac Wings did 1/72 kits of the X-24A/B and the M2F2. Nice vacform kits, but need to bring your own cockpit and landing gear. Anigrand did them in resin as well.
I would LOVE to have MPM/Special Hobby or ClearProp! do them in injected plastic. Hobby Booboo need not apply - you might buy an HL-10, but open the box and be surprised by an M2F2 inside! Kinda like the opening title sequence to “The Six Million Dollar Man”.
Go to fantastic plastic and look through their collection section for the 1960s. They lost both and who made them. Now, if they had a scale figure of Steve Austin, that would go well with them, or mount it to a early B-52.
I saw Lee Majors crash one back in the 70’s when he was worth 6 million dollars.
Eagle’s Talon 1/72 vacforms. Both excellent kits, but hard to find now.