I still do some stick and tissue kits for grins and giggles. Gillows has some fine kits. I went into a hobby shop some time ago and told them I wanted to buy some DOPE and they called the cops. Try finding the old Pactra DOPE.
If I recall correctly the X-3 was supposed to get us into the Mach 2 range, but never lived up to its expectations. Look at its wings and then look at an F-104. I would like to see a Bell X-5 in 1/48th scale, er Me 1011.
Anybody remember sonic booms, hiding under your desk at school as a way to survive an attomic bomb attack, lining up at school to get the polio vaccine and other prevention shots. The 50s were an intersting time.
If you get the early Lindberg kits they are usually the proto-type of the aircraft, e.g. the F-100, F-8 Crusader, the AD 4 Skyhawk, the F-104, etc. The kits were later modified to represent production versions. Lindberg was consistent with scale and not like others using "box" scale. Monogram was also scale consistent with 1/72, 1/48, and 1/32.
Back then you had to have an FCC license to fly Radio Control models AND part of the test to get the license was knowing Morse Code.
Cheers