I always associated royal doulton with fairly expensive porcelain china...
if it is this Royal Doulton - Gordon Ramsay by Royal Doulton Stainless Steel Cookware - Page 1
line it looks pretty nice and is certainly expensive enough. The specs are all in line with HQ cookware
They probably contracted out with some other manufacturer to make the cookware and branded thier name.
They are a high end brand name though so I doubt they would brand a cheapy pot... but you never know with brand names these days
I would go by looks and feel. but if it is tri-ply w/riveted handles 18/10 stainless you are in pretty good shape