Really depends.... I restored and eventually sold a 76 Viscount Aerospace Pro and it was close to catalog specs. It was such an iconic bike with the weird components, it was great fun to build and source the parts.

This year I built up a 76 PX-10 and I went pretty much full period correct Campy NR, except for brakes & bar/stem. If I had a PX-10 back in the 70's, I would have wanted to upgrade all that plastic Simplex
stuff, Lyotard pedals and steel seat post. Would have liked to keep the Stronglight cranks, but AFAIK they were only available in 170mmm & I prefer a longer crank.