"Nothing is ever 100% in tact"
Ian, I assume, is absolutely correct.
And yet: some courses *appear to be* 100% in tact
Might that not be the much more telling, and important, fact and consideration?
An analogy: a great modern course, on the first day of opening and solely because of the skill and craft of the design team, 'looks like it's been there for 100 years', when in fact (in truth) it's brand new.
Well: maybe the truth here is not nearly as important as the fiction -- especially as the 'believable fiction' is a major part of that course's quality and charm.
It's a trick, yes -- but what's the alternative?
Similarly (though this may be heresy to some): why should anyone care a whit whether or not a course has ever been altered, especially if/when it *looks like* it hasn't been?
After all, G-D didn't create it originally, some architect did, maybe a good one or even a very good one. And if G-D didn't make it to be eternal, it's not, only ever fleeting -- and besides, there's been a lot of very good architects since then.
Maybe the better question for a site like ours is: what courses have been so wonderfully tinkered with by such top-flight talents that they can *fool* even the most experienced eye into believing they've never been altered?