Well, Kent, I have to smile and laugh a little bit at your comments regarding auctions.
In one respect you're dead on right; Auctions are all about dollars!
Can you imagine bringing your gun to an auctioneer and having him say 'Great gun, I'll sell it for as little as possible to give someone a great deal!' I'd guess that guy would be out of business in short order.
As for the guns we're interested in, Kentucky rifles, for the most part they come down through time with absolutely no history. If your lucky, there might be a previous owner known, or maybe a few on the Great guns. As for work done on them, there's pretty much no history. Add that to the fact that these guns were being restored at least as early as Dillin points out in his book of 1924, and you have a huge black hole!
To move on to today, you have an auction house that might be handling a thousands of items at a large auction, with maybe less than 50 being Kentucky rifles. Now, I don't know how many appraisers they have, but I doubt appraisers have more than an hour per Kentucky rifle to determine what it is and what's been done to it over the past centuries, and write up an appraisal. And you really think, or expect, that they're going to get it exactly right all the time?
I know you're new to Kentucky rifle collecting, and it takes some time to learn what's what. The best advice I can give is to look at the pictures of a gun in an auction and judge for yourself based on what you see. If you don't think the lock in the Graeff is original, don't be surprised. Lot's of these guns have an early restoration, and then a later one to fix the errors of the early one.
In the end, just remember buying from an auction requires you to do your home work and have a sound knowledge of what you're interested in. I don't believe a reputable auction house will lie to you outright, but also realize that they might not be correct on every detail.
We have an auction appraiser on this forum, and maybe he can elaborate on this better than I.
John