Melvyn, I read at least 5 references to yardage in the article you posted. Most are in the context of describing the length of a putt or accuracy of an approach to the pin, but another refers to a player being "40 yards short of a bunker." That seems significant to this topic, as it sounds like yards were already the preferred unit of measurement in the day of Old Tom Morris, though perhaps players didn't need to know their exact yardage for every shot.
Perhaps if someone had handed Park a range finder, he wouldn't have come up short and hit his approach into that aforementioned bunker.
The article also gives a lot of reference to half-shots and quarter-shots, and describes the club used for each. It's interesting to read this and realize that players carried fewer clubs and thus controlled distance by fractional shots as opposed to just pulilng a different club. It makes me wonder just how "calibrated" those shots were.
For instance, I know exactly how far I hit half-shots with most clubs up to a 5 iron, and with quarter-wedges. Were Morris and Park truly just "playing by feel (which, to me, means they looked at their target and just let their subconscious swing the club, as most of us do when putting)," or did they have a keen idea of how far they hit the ball with different shots and actively choose between a half-cleek and quarter-mashie? To me, that's more like executing a "stock shot" and more along the lines of what Dave Pelz started recommending to players in the 1970s.