One feature that stands out at my club, which couldn't better be described as a relatively untouched golden age course with no design pedigree, is irregular, or rumpled fairways. It seems on many contemporary courses the fairways are obviously graded and smoothed. I don't think this would have been the case on a modest course of that era.
Similarly, because there's no or little intentional mounding in the fairways or green surrounds on our course, at least, there's little gathering effect. Balls bound where they will, unless there's a natural feature like a punchbowl that collects.
On greens, push-up greens are not uncommon. As with the fairways, I would expect more irregular, micro breaks within the greens, and fewer broad sweeping contours. Also, I would expect more concave greens, and more back-to-front greens. If my course is any example, if the ground gave good enough motion as is, it was used as is. If it didn't, push some dirt up in a mound and make that the green.
The better golden era courses I've seen use visual deception regularly, with infinity greens, top shot bunkers that create blind landing zones, guardian bunkers set well forward of greens, etc. A common bunker shape I've seen is a rectangular bunker with a built up mounded face. One can imagine the dirt was shoveled out, forward, and up, then regrassed.
Finally, I've seen a number of courses with contrived, but artful, hazards, notably on Par-3's, like a ring of bunkers like a pearl necklace, or the moat style bunkering of a short hole. Rectangular greens show up, too.