Tom,
I haven't researched the era as extensively as you have. I do think you are smart to realize how much things did change in those 20 years. In many cases, I think we tend to think of "the old days" as sort of all happening at once, but in reality, there were more changes in gca in those 20 years than there have been circa 1989-2009 because the craft was just developing in the US. And, that level of understanding might make a difference in our modern interpretations.
I actually haven't got a clue if the meanings were different in 1890 and 1910. But, I don't think anyone else really does either. Basically, DM and Mike C have both presented contemporaneous examples of the word being used in the ways they support as its basic meaning. It appears to me that people used the word in many ways so we can't rule out just what MCC meant.
Nor do I think parsing words like that means much in this context, other than the basic facts are going against you. Basically, it is the nature of lawsuits and disagreements of any kind. When there is a disagreement, the argument will eventually go to areas that are the least defined as each side makes their points.
That is what is happening here. You and DM want to prove the MCC history is wrong. (yes, I know, you want to find the truth) The basic timeline according to meeting minutes shows one thing. So you start picking around the edges, like parsing every frickin word someone used, including blueprint, expert, etc. You elevate those kinds of incidences - a choice of words - to prime importance in the argument over other documents.
Probably the biggest argument you could use is the old "An expert is a out of towner with a briefcase." That alone makes Barker a bigger expert than anyone at MCC. I am surprised you haven't pulled that one out of the hat yet! Of course, TePaul and Mike C would argue that this saying really impllies that many realize that they know as much as the experts and refuse to pay for expensive advice when they can do it themselves. And so it goes on.
Jim Sullivan is right - we simply don't know. It is getting a lot less fun to be on golfclubatlas.com because of this endless arguments. As a friend of mine says, "when its not fun anymore, its just not fun anymore". Obviously, he is channeling Yogi Berra. But, he is right. The biggest question for me right now is not what expert means, its whether this site is even fun anymore and worth the time.