Back when wasn't as long ago as you seem to think!
Not an airliner, but as recently as ten tears ago, I was flying an IAI-1124 Westwind with no FMS or IFR certified GPS. We flew airways by reference to VORs and had to do NDB approaches occasionally. At least we had working RMIs and dual VOR and ADF receivers. In that way at least, we felt like we were flying in the earlier days of aviation!
We learned a trick from the airlines about using our VFR GPS to fly direct routings though: Somewhere over Southern Utah; Ahh Salt Lake Center Westwind 123 at three-three-zero on a vector of zero-six-three direct Hoxie. Salt Lake: Roger 123, continue on self-vector to Hoxie! In the year 2000, that's exactly what Fedex and several others were doing and we followed their lead. Maybe one controller in 10 would vector you back to airway. It was so much nicer when flying the other Westwind with it's UNS-1 and easier yet when I got hold of my first glass panel plane.
Someday in the not too distant future, someone will post a question on PPRuNe about what it was like to fly an ILS!