I don't know what we pre-Jonesers (I was born in 1950) are called, but here's one perspective on the 70's (btw, Pink Floyd, Fleetwood Mac, David Bowie, Yes, ELP, Simon and Garfunkel, Led Zeppelin, and King Crimson would have been familiar to us pre-Jonesers by 1970).

For me, the 70's were the florescence of the Canterbury school of music, which had strong roots in the late 60's. Hatfield and the North, National Health, Gilgamesh et al. released a series of sophisticated, challenging prog unlike anything from other prog schools, and the 60's Canterbury musicians continued to evolve--Soft Machine (including solo works by Robert Wyatt and Kevin Ayers), Caravan, Gong continued through the 80's and in various incarnations to the present day.

They probably wouldn't be classified as progressive, but Velvet Underground alums Lou Reed, John Cale, and Nico unleashed a series of challenging and important works.

And the Kinks survived the 70's with a series of innovative albums that are to this day underrated by critics.

So if you want a pre-Joneser perspective on 70's music, it would be the above works. Other pre-Jonesers will no doubt have their own favorites.