Brett,
I can tell you that I have never (in 33 years as a gca) had any involvement with designing or adding distance markers. That is usually a function of the owner/managment group to do after construction but before opening.
Interesting that CP had the 150 yard markers, apparently. I know that since I have been playing golf (1967 start) some form of yardage markers were common. Usually the little bush.
At Medinah, I recall they had a yardage book that referenced different trees. There were so many, I sometimes wasn't sure which one the book was referring to, but it was my first round of golf!
Some courses had the barber poles at 150, and some had three markers - red, white, blue (and sometimes yellow) for 100-150-200-250 out.
Other courses had the metal plates instead of poles, but the poles are more visible and were favored (along with the bushes). In the 80's, a company made a rubberized plate with small bump so those could be seen from distance.
Some clubs added colored road bumps (city titties, as we call them in Texas) in the path, color coded. Others painted stripes in the paths, same color code as the poles and plates.
Also in the 80's, was the first time I saw the each sprinkler marked, sometimes the long ones (250 out) said something humorous like "No Way!". With the advent of the Pelz technique, I am surprised more courses don't have the markers less than 100 yards out marked for distance control, perhaps even the ones around the green!
As your post suggests, I don't think the advent of yardage marking started just when I started playing golf! It would be interesting to flesh out some of the details.