I live close to HQ Milton. I'm very confident their watches are what they present them to be. They have quite a lot of loyal customers *I'm told* who trust them. Trust but verify. If they were to pass of 1 or 2 frankens, and get caught, their income stream in the near future would suffer greatly, and they know that.
At a show it is buyer beware. It often takes some time to compare magnified hi res pics to known gen sources to find the best fakes, but it can be done. I'm still waiting for dial reprinters to get the alignments just right. I haven't seen that happen yet.
But yes, of course, some people will try to cheat you if they can.
I was sold 2 different 1680s, one white and one red, they were gen except for the rep hands. After being politely pointed out to the seller, he supplied me with gen hands he just happened to have in stock.
I don't find it that difficult to post pics of claimed gen vintage rolex on rolex forums and see what they come back with. They may call out a gen as fake, but I've never seen a rep pass muster if it had a rep dial.
Superfrankens with gen everything except rep case would be the hardest to catch, yes. But this assumes access and the $$$$ required for a gen dial.
But honestly, who really has access to gen rare vintage rolex dials? You are going to have to pay tens of thousands for just the dial.