I can speak to the camera I just purchased from Tamarkin, M6TTL rated as Mint -, and my recent purchase. When I asked the salesperson, Craig by the way, to compare a few cameras we had discussed he indicated that mine was the cleanest in his eyes, but had the plastic removed from the bottom, the others still were in their "wrapper" (also Mint - and Excellent+ all more or less the same price). Wanting a camera to feel comfortable using, I chose appropriately. I have to say, other than a couple fingerprints, my camera is like new in my eyes.
I am confident that both Tamarkin and Photo Village rate their used cameras accurately. Craig mentioned a number of times in the 3 or 4 conversations we had that Tamarkin wants to be sure that their customers are happy and have the right camera for them. He repeated the 10 day return without question test period and warranty provided with the purchase. I found both Tamarkin and Photo Village to be respectful of what I was looking for and my budget and didn't pressure me in the sale in any way. My opinion is that they know they are selling a highly reputable item, purchased by individuals looking for the best, and so they are looking to satisfy that need in us.