I'm here to join you around the campfire and add two experiences and perspective. You're not alone. I am new so be nice.

1) I found my ideal in an "affordable" matched best pair of London SLE's and went over the guns over the phone with the dealer. They were consigned guns. My first call regarded general information about them. I followed up later with a second call to discuss condition; he put down the phone to retreive the guns/case and said "Let me take them out and go through them." We spoke about any cracks or splitting in the stock, loosening of forends, asked about the barrels ringing true, loose ribs, about dents or bulges, about off-face, about wall thickness, do the triggers fire etc. The advertisement described them as shootable and he repeated they were. He was obviously going over them with me on the phone, bit by bit. Everything checked out, and even advised the wall thicknesses measured some 31 thou. He even stated that the case came with the original crystal oil bottle. The guns had no issues, just obvious checkering wear which were going very light, and as a positive for me the measurements of cast-off were fine, although it was described as not going through the metal/tang. These conversations felt very detailed. Yup, so i put my money down and paid the their $150 for insured shipping (cross-country for heavy case/guns) and a three-day inspection.

Here's what i got: Obvious old split in an underside stock finger; bulge in one of the barrels, the other barrels didn't ring true (they had a dead spot in them), wall thicknesses in fact miked to about 22 thou., and the kicker is one of four triggers wouldn't fire. Also, the tangs did bend with the cast (no big deal for me, but obvious on first sight). And finally, no crystal bottle was included! The dealer photo of the set displayed the crystal bottle in the case. Um, since when are either of these guns shootable?

What did I do? Of course I had to consider the near total potentially of $300 lost on shipping charges should i return them, however I thought, just extend my inspection period so that i could have the time to find a most-reputable English trained gunsmith review the guns and give me an adequate estimate for the repairs. He agreed. The repairs in fact would cost much less than i expected, the guns did appear meticulously maintained, the wood otherwise was great, and so I kept the set. I did confront the dealer, who was always pleasant, and he simply had nothing to say other than that none of the above was obvious and that consignment guns are those that any dealer would not get checked out on their own dime by a true gunsmith, so i was essentially told caveat emptor and "you can return them if you are unsatisfied." To his credit, I did get a $$ check to make up for the lost oil bottle.

2.) I had picked up several vintage US-made doubles and sight unseen (in-person, that is) had them instead directly mailed to a reputable known niche gunsmith/maker who was considered a subject matter expert on this particular manufacture/model of sxs's. He's participated in and won in a Gold medal Concours D'Elegance. I requested that he perform the 3-day inspection on each. Wonderfully each passed muster. I asked that a couple of the firearms be restored as closely as original, including case hardening, recheckering, etc... the gamut. I expressly advised I wanted Doug Turnbull Restoration to perform the case hardening on the receivers. I was quoted the prices. I accepted and paid a deposit on the hardening work to get the process going. I followed up with express written correspondence to my gunsmith/maker for the restoration work to be done by Turnbull. After the receivers came back i asked how they turned out, my gunsmith/maker said wonderfuly. Little did he know i would write Doug turnbull for a company letter stipulating that they had performed the work on my serial no'd receivers, and sure enough Turnbull's company called me and said "You know the letter you sent us asking for verification on the work? We never did it!" After confronting my gunsmith/maker he admitted he sent the receivers out to a different vendor. He lamented that his work was backed up/he had travel/he would have had to pay higher charges from Turnbull etc. etc. I was very angry and sent some letters to very pertinent people everywhere. Needless to say i got a discount and the work turned out fine. But this was crazy ~ not what i expressly demanded for the restoration! Lastly, the one gun which I did not ask to be restored but merely to be stripped-and-cleaned, well it came back with a loose forend. Of course I had been told it checked out when my gunsmith/maker did the original 3-day inspection on it (and of course the seller had said it was fine when I purchased it).

Whatever happened to full disclosures and ethical conduct?

I have common sense and have read the books; be specific as all get out, follow-up with letters, specify. But it still didn't help.
I am sorry but my two short experiences ruined some of my initial collecting interest; I sort of view dealers and gunsmiths now with a wary eye, not unlike you view a used car salesman.