Jeff:
You raise a couple of fascinating questions, which I'll lay out in rambling form:
1. As Ally asked earlier, at what point is a course built? There were courses originally laid out that the architect knew would be a work in progress, with much of the "final" design depending upon how the original ideas morphing as they were built and played and changed. There were also courses that started as a strict translation of a design on paper into a course on the ground, and were later altered as those that played the course realized that there may have been a misconnect between the original concepts and how they actually worked with the ground. There was a different intent and model of creation for the "labor of love" course v. the "tour by train" architect.
So how do you choose a date? For the former, do you take Pinehurst #2 at the time the full 18 was first open for play, or do you take it right after Ross made his last change to his masterpiece? For the latter, for a course like Clearwater do you look to the date of the original layout, or do you say the course was done after Maxwell came in and added character to the greens?
2. So much changed in the way golf was played from 1895 to 1940 that change was almost inevitable. For a course like Chicago, the changes in the ball alone probably meant that the original Chicago Golf would have been obsolete a long time ago if Raynor had not come in to make improvements. What I don't know is whether or not what Raynor did was simply an extension of the original ideas formulated for the holes by MacDonald, or some sort of translation. Did he change the nature of the course, or did he simply modernize it?
3. Does natural alteration come into play at all? Blowout bunkers change in shape, move and effect their surrounds all without the influence of man. Trees grow and narrow corridors, block angles and effect turf conditions.
4. Perhaps the question we are asking is what courses still play to the intent of the original architect? Does this lead us to a discussion of what styles (or strategies) have had staying power, and thus changes may not have been needed? I would think that courses that demand the ground game be played would have the best chance of not being overwhelmed by the way the game has changed, as would courses that offered limited options off of the tee via the use of crossing hazards, dog legs and the creation of optimal angles and distances.
Much of this seems to this layman to lie at the heart of the renovation/restoration process. You would know better than I the decisions that are made when deciding to make changes to a classic course. Do you try to recapture that original intent, perhaps on a bigger scale, or do you take the course in a new direction?
Sven