I agree in terms of airframes and aero structures, etc. we won’t see the 50s & 60s again. I still get surprised reading an old space tech news article saying “we were doing THAT 60 years ago!”
Musk himself did not got around staging, his real stroke of genius with BFR / BFS is to make the first stage reusable (done with Falcon 9R, clever guy) and the second stage a multipurpose vehicle - second stage, TMI stage, cruise spaceship and Mars lander ALTOGETHER.
Compared to Stephen Baxter / NASA standard Manned Mars ship, starship by itself take over all the jobs - S-II injection stage
and S-IVB return booster
and Skylab-like interplanetary cruise ship
and MEM lander
and Apollo atmospheric return capsule.
This is amazing when you think about it, folding all this separate missions into one and only vehicle. Radical, bold, although pretty risky, too.
I can tell you that, from 1955 to 2015, nobody ever thought or tried to build a... TSTO to Mars surface from Earth surface.
Closest thing from BFR/BFS I can think off, is this. Boeing 1976 Space Freighter, imagined for O'Neill Space colonies.