Staffordshire Dogs

I have cleaned the dogs and the brown stuff is mostly gone, if anyone has an opinion of the dogs I would love to hear it!

Two Stafforshire Spaniels, the tallest is 12".  The gold on the chains is worn.  There are firing holes on the bottom and on the inside of the front legs.  As you can see, they are not idenitcal, one dog's chin is lower and the paint strokes don't match. They are heavy, around 3 pounds each, one is slightly lighter than the other.  The glaze on the bottom is the same as the rest of the dog.  One front leg is not molded to the body. 

Any information about the potter's mark and the age and value would be appreciated.