I use to own a 2007 Mercian Vincitore Special, it was a very nice bike, too nice! I sold the darn thing because it looked like a piece of art and I was literally afraid of scratching the paint so I rarely rode it and sold for what I paid for it to a friend who was begging me to sell it him for months, I finally relented knowing that I wasn't going ride it anyways, it had maybe 20 miles on when I sold it after owning for 10 years. I had it equipped with Campy Athena skeleton silver components.
I should have never bought the bike, it was a impulse buy that I usually never do. But if buying one used the scratch paint issue is not a problem, I would HIGHLY recommend that you buy that bike, it's entirely handmade the real old fashion way where they heat the tubes so not to localize the heating in a small area in an oven then braze using silver at very low temps, it's the best way to braze lugs onto tubes, but it's labor intensive and the silver cost more than brass.
This is what Mercian says on their website about the above technique:
Open Hearth Brazed:
Mercian have brazed frames in an open hearth, since the 1940's, as we believe this reduces the possibility of overheating the tubing, unlike a welding torch which can be too harsh in the wrong hands. Open hearth brazing, in our experience, is much kinder to the lightweight metal tubes and also means that should a frame tube be damaged in use, we can undo the braze and replace a single tube meaning your frame gives you many years of pleasure.
So YES YES YES buy that bike.