Soup Tureen, Royal Staffordshire Pottery, Marseilles pattern,

I am interested in an appraisel and background of this soup tureen that I own.  I also have other pieces of the set, though not a complete set.   I have found very little, if any current information online about this pattern from Royal Staffordshire Pottery.  Item to be appraised:  11" Oval Soup Tureen includes lid Marked on underside:  Royal Staffordshire Pottery, Marseilles (Pattern?), Burslem, England, F, C, gold mark on bottom of dish and lid is non-descript The color is a blue-green and a there is evidence of a very minimal 'flow'.  The condition is good to excellent, no chips, no cracks, gold edge is very minimal worn off, no crazing,has manufacturing imperfections under the glaze Other items I own in the same pattern:  (qty 5) 10" Dinner Plates, (qty 2) 8" Soup Bowl, (qty 2) 6 1/4" Bread & Butter Plate, (qty 3) 6" Saucers, (qty 3) Tea Cups & Saucers.  The quality of these items range from fair to excellent.  Hope this is everything that you need to help me out!