At the recent boat show here in Seattle, Dufour had a good representation with a few models on display at the 'in water' portion of the show. I certainly don't think it's an unknown brand and it seems Dufour is making an attempt to increase market awareness here in the US, so if the survey is good go for it! Meanwhile, see what research you can do on that particular year through some UK websites through google. You may find some pointers through some Brit chat rooms.
S/V Don't Panic!
“Navigare necesse est, vivere non est necesse” To Sail is vital, to live is not.